Upper Cliff Dwelling Trail

Enjoy this rare opportunity to "hike" to the Upper Cliff Dwelling. About 80,000 people visit Tonto National Monument each year. About 1600 of those visitors participate in the guided hike to the Upper Cliff Dwelling (UCD). Approximately 5% of all visitors, since the park’s beginning, journeyed to the UCD. Physical limitations prevent some from climbing the 600 feet during the 1.5 miles (3 miles round-trip). Others arrive May through October when high summer temperatures put a stop to UCD hikes. Many are not aware of the need to make reservations for the small group hikes.

Those visiting the desert more than once experience the changes -- season by season, year by year, green and lush, dry and hot. This virtual hike portrays some of the desert’s varied scenes. With QuickTime installed and mouse in hand, explore some of the 360° images. Most of all enjoy!


Stop #1 – Introduction

Walking barefoot or in yucca sandals, the Salado climbed the hill to their home close to the top. Did they follow game trails or have a specific trail? How often did they journey to and from the dwelling? They left no evidence to answer these questions.

The trail to the Upper Cliff Dwelling (UCD) changed over time. After climbing 350 feet to the Lower Cliff Dwelling, early park visitors then crossed Cholla Canyon Wash, followed game and cow trails along the side of the hill and climbed up the ridge leading to the UCD. About 1940, part of the current trail was developed. Horses needed an easier path to carry supplies for the dwelling stabilization work. Later, flash floods damaged the part of the horse trail through the riparian area. The path seen on the map is the old trail. The first part of the trail now winds through much of the wash before joining up with the old horse trail again.

Due to limited excavation, valuable resources and information remain within the dwelling. In 1948, travel to the UCD became restricted to ranger led trips, to prevent further damage to the cliff dwelling and protect its resources. This continues to be the practice, even today. Advanced reservations are required for the guided hikes available three to four days a week from November to April. To enter this protected area, strap on your yucca sandals and be sure to watch your step.


Stop #2 – Micro-environments

Within a short distance, the Salado had many sources of food, medicine, clothing and tools. Plant knowledge and use passed from generation to generation. As a result of different climatic conditions, the two slopes and wash forming Cave Canyon each support different types of plants. The rays of the sun hit the eastern-facing slope directly, resulting in warmer soil with little moisture. Saguaro, ocotillo, cholla, and palo verde are a few of the plants commonly seen on these slopes. Striking the western-facing slope at an angle, the rays of the sun do not warm the ground, resulting in cooler, moister soils. Agave, sotol, and several types of perennial grasses prefer this soil. Both wet and dry riparian areas exist within the wash at the base of the canyon’s slopes. Some of the plants needing the moister riparian areas include Arizona black walnut trees, mesquite tree, catclaw acacia, blueberry elder tree, and Arizona dewberry.

The distinction between the four environments is more visible during spring, summer, and autumn, especially around the riparian habitat. With the right conditions, each environment’s plants and wildflowers bloom. In spring, new leaves bud to form the canopy of the riparian area, light green after a winter of bare branches. Summer, the hillsides appear dry and dull in contrast to the rich green of the tree canopies below. Much later, after summer monsoon moisture, the hillside plants perk their green up, while yellows and oranges color the autumn tree leaves. These micro-climates are an amazing part of Sonoran desert life.


Stop #3 – Water

Upon entering the riparian area (panorama), one might easily forget the surrounding desert. The shade of the tree canopy filters the harsh sun, immediately cooling the air temperature. Patterns of shade and sun dapple the surrounding landscape. Gently moving water reflects the leaves overhead. The water moves down the canyon a short distance before it disappears back below the surface. Do not become too complacent by the beauty. Though water supports life, it is also an impressive, sometimes deadly force.

Erosion’s powerhouse is water. During heavy storms, water collects in various washes, finally joining into one wash. Sudden walls of water roar down, gaining momentum, damaging everything in their way. As long as it flows fast enough, rushing water carries loose rock and minerals. The debris-laden water scratches and fractures rocks along the wash. As the water slows down, the heavier rubble falls out. The remaining fine particles smooth and polish rocks along the way. Over time, water sculpts cliff faces, carves canyons, and wears away hills.

Washes and arroyos play an important role in the desert. Animals travel through the dry corridors. Seeds are dispersed through these areas by animals and flowing water. Most importantly, washes throughout the desert wait, sometimes for years, to fulfill their naturally designed purpose: channeling flash flood waters from sudden intense storms.


Stop #4 – Springs, Seeps, and Tinajas

Sources of water exist in any arid environment. Long-time desert dwellers know where to look. Where does the clump of green bushes obtain water when all surrounding vegetation is low lying and faded green, yellow or brown? Does the grouping of tall deciduous trees have roots reaching deep for water or does a year-round spring rise to the surface beneath the trees? These are only a few of the water source signals visitors to the desert might miss.

As long-time desert dwellers, the Salado must have used water signs as they hunted and gathered among the hills. Cave Canyon Spring provided a dependable water source, allowing the Salado to build in the caves. It is easy to imagine the cool, shaded area as a meeting and working place. A basket or mat maker might have worked in the shade of the trees as their plant materials soaked in the water. The Salado must have valued artistic beauty and creativity. Their pottery, weaving and other crafts display an attention to detail and a fineness of craft. Did they also value the natural splendor around them as well? As they sat among the trees to work, did they enjoy the sound of trickling water and singing birds?

Springs and rivers are relatively permanent sources of water. Other sources come and go. New and current water sources increase during wet seasons and years. The opposite is true of dry seasons and dry years. Geologic episodes may change water pathways above and below the surface; and, in turn, change locations of temporary and permanent water outlets. Considered temporary water sources, seeps slowly trickle, sometimes forming pools. Shifting rocks might close one seep outlet only to open another one nearby. Seeps increase flow in wet times and decrease, even stop altogether, in dry times. Another temporary water source, tinajas (te NAH has) mainly depend on weather. Water collects in rock depressions. The moisture cannot escape and waits for evaporation to end its usefulness. The deeper the rock depression, the longer water lingers for use. Areas protected from the sun’s heat retain their moisture even longer.

Throughout the year, many wild animals rely on the monument’s water sources. Tinajas disappear within days of moisture providing storms. Seeps appear in wet years, vanish in dry years, only to emerge in new locations. Despite other changing water sources, Cave Canyon Spring is constant. Composed of tight structures, the rock formations of the monument do not move or store much water. Since it cannot flow through, water finds routes around blocks of impermeable rock. Faults, fractures and looser structured rock layers become miles of water pathways. Cave Canyon cuts deep enough into a pathway for water to surface as a spring. The water journeys a short distance along the canyon before sinking back into the ground. Both the surface and underground water support a unique habitat of plants and animals. In 1992, U.S. Fish and Wildlife Service listed Cave Canyon’s riparian area in their national wetland inventory.


Stop #5 – Riparian Communities

Existing along the banks of waterways, riparian zones support a large variety of plants and animals. Many animals make their permanent home in the plants and rocks along the stream course. Others use the wash as a travel corridor, a hunting site, or a seasonal migration rest stop. During the driest of times, temporary visits increase as the animals rely more on riparian food, water, and shelter than they needed to before. Cave Canyon is an oasis of abundant life. Protection within Tonto National Monument will allow future generations to experience its beauty.

Riparian Corridor Animals at Tonto National Monument

In Arizona alone, 28,000 insect species, 111 bird species and 45 mammal species live in or use riparian areas. Below, you can learn about some of the many animals using the Cave Canyon’s riparian areas.

Antonia’s Hackberry Butterfly

Other Common Names: Empress Antonia, Antonia
Scientific Name: NYMPHALIDAE, Asterocampa celtis antonia

Description: Butterfly: medium sized; wing spans -- male about 1 3/8 inches, female larger to 2 ½ inches; 3 pair of legs; yellowish-brown color with white spots near the fore wing tips and two dark spots along the outer wing margin, a band of dark spots and two dark lines on the hind wing. Caterpillars: to 1 ¼ inches long; green with a pair of yellow lines along top of body, v-shaped markings on sides, tapered at both ends; branched pair of knobs on head; end of body has two projections or “tails”

Habitat: riparian areas where netleaf hackberry trees grow
Diet: netleaf hackberry -- caterpillars rely on leaves and new growth, adults feed on sap flows at tree wounds
Predators: insect eaters

Other Information: Hackberry butterflies are part of the brush-footed family. This means they only walk with the hind four legs. The front pair of legs is half the size of the other pairs. They are covered with hairs and look like small brushes. These “brushes” have scent receptors to help recognize food plants. Caterpillars hatch from eggs, some laid before winter. They develop through several stages before forming a green chrysalis to change into a butterfly. The butterflies are active May through September. Three different generations of egg through butterfly occur each year.

Arizona Black Rattlesnake

Scientific Name: VIPERIDAE, Crotalus viridis cerberus

Description: about 15-42 inches in length; day -- a background and blotch color of jet black with blotches outlined by yellow, night – background color lightened; young snakes change from overall light brown through light gray to finally jet black after several skin sheds; retractable fangs

Habitat: wooded canyon areas
Diet: small mammals, ground-nesting birds, lizards, amphibians
Predators: badgers, hawks, kingsnakes, javelina, whipsnakes, ravens, eagles, bobcats, coyotes, roadrunners

Other Information: The Arizona black rattlesnake is a subspecies of the western rattlesnake. This rattlesnake is dangerously venomous, but is less easily provoked to attack than other rattlesnakes. It is active April through late fall. Breeding begins in April. The births of three to twelve 10-inch young snakes happen in August or September. During the cold months of inactivity they den in small numbers or alone. Rattlesnakes play an important role in limiting rodent populations. Some of these rodents carry diseases harmful to humans.

Black-chinned Humming-bird

Scientific Name: TROCHILIDAE, Archilochus alexandri

Description: up to 3.5 inches in length, weigh between 3 grams and 4 grams; long, pointed beaks; small feet for perching only; both male and females have metallic green backs, male has black chin or throat bordered below by patch of iridescent purple, female have pale gray or whitish underparts and white outer tail feathers

Habitat: live in dry desert washes, but can live in a variety of habitats; nests in a branch fork near or over water
Diet: nectar, small insects and spiders
Predators: small hawks and owls; spiders when caught by large spider webs, roadrunners; snakes eat the eggs and young; other animals have been known to eat hummingbirds when opportunity arises

Other Information: After wintering in Mexico, the black-chinned hummingbird is a park resident April through August. Hummingbirds are important flower pollinators, distributing the pollen as they fly from flower to flower drinking nectar. Besides providing most of the liquid they need, the nectar supports their high metabolism rate. With up to 80 wing beats per minute, energy is quickly burned. To save energy, a hummingbird goes into torpor, a state of temporary hibernation. Body temperature and heart rate drop and breathing may stop for a few minutes at time. This state also prevents moisture loss during hot, dry times. The male swings back and forth in an arc to attract the female. Pairs are together only long enough to mate, then the female takes care of everything else. She weaves the nest out of plant down and lichen, binding it together with spider webs, and then, lays two white, bean-sized eggs. Gathering enough food to feed herself and the young is a major task. The nest is flexible enough to expand with the growing nestlings. The same nest site may be used again with the new nest built on top of the old. Some native people of the southwest considered hummingbirds as messengers of the rain spirits, their bright colors similar to rainbows. The ancient Aztecs believed their bravest warriors who died in battle would be reincarnated as hummingbirds. We’ll never know what the Salado thought of these small colorful birds.

Canyon Treefrog

Scientific Name: HYLIDAE, Hyla arenicolor

Description: about 2” in length; warty skin; olive to grayish-brown with greenish-brown spots or plain; dark edged light spot under eyes, yellow to orange under legs; males have yellowish-gray to black throat, females white to cream throats; distinguished from toad by round toe pads on all four feet

Habitat: rocky canyons with some permanent water
Diet: insects of various kinds
Predators: snakes, fox, raccoon, ringtail cat, coati, skunks, and many others

Other Information: This nocturnal treefrog tolerates cooler temperatures than other frogs, but is able to retreat underground during the coldest times of the year. May through July, the male calls with an explosive series of notes, all of the same tone. Lasting one to three seconds, the male hopes to attract a female to its mating site. Mating depends on whether enough rain falls. The eggs are laid in a large mass and float on the surface of water and hatch into tadpoles. The treefrog clings to twigs and climbs vertical surfaces because of its adhesive toe pads. During the day, it hides in rock niches and on stream banks. Being the master of camouflage, it usually does not move until a potential predator is on top of it.

Gila Monster

Scientific Name: HELODERMATIDAE, Heloderma suspectum

Description: up to 22 inches in length; weighs up to 5 pounds; short legs; strong claws; large head with black face; small, bead-like scales patterned in colors of black, orange, yellow, pink or red; short thick tail

Habitat: deserts and desert grasslands; elevation to 5,000 feet
Diet: nestling birds and baby mammals, easily accessible bird or reptile eggs
Predators: hawks (primarily the Harris hawk), owls, coyotes; rattlesnakes and other reptiles eat the young; humans create problems through habitat destruction

Other Information: The Gila monster is one of only two venomous lizards known to occur in the world and is protected by law. The bead shape of the scales is created by osteoderms, small bone particles embedded in the skin. These create a tough hide on the back, head, legs and tail. The underside has flat scales without osteoderms. The Gila monster’s plump tail is an indicator of health. Both water and fat are stored in the tail. Both are used during dry times or during hibernation. A thin tail can indicate dehydration or starvation. Venom is not injected, but is pumped into the open wound as the lizard chews on its victim. Spending approximately 98% of its time underground, the Gila monster uses two different burrows. A higher burrow close to rock outcroppings is used in the winter and early spring. Lower levels provide a cooler and moister burrow during warm months. Active times of the day depend on the season – day during warm months; night and evening during hot months; and hibernation during coldest months. These shy creatures are not often seen, even when basking quietly in the sun for they blend with their surroundings. It prefers living near water, so is a frequent visitor in the riparian area.

Javelina (Pronounciation: hav a LEE na)

Other Common Names: collared peccary
Scientific Name: TAYASSUIDAE, Pecari tajacu

Description: weighs up to about 55 pounds; length up to 30 inches; short legs; coarse salt and pepper hair covering body, band of lighter colored hair rings the neck and shoulders; pig-like snout with long sharp canine teeth called, “javelins”; young are reddish-brown turning gray as they age

Habitat: prefers shady areas of dense vegetation and shallow caves
Diet: prickly pear pads, mesquite beans, roots, seeds, tubers, green vegetation, cactus fruit, agave, and dead birds and rodents if available
Predators: mountain lions about only animal willing to attack an adult;

coyote, bobcat and other animals will prey upon young javelina

Other Information: Though the javelina have the pig-like snout and eyes, they are not a wild pig or boar. They are smaller than pigs and have no large tusks. They are the only US member of a mammal family common in Central and South America. The young, numbering two, are usually born in July and August. An older, experienced female leads the family groups of up to 20 individuals. They have very poor eyesight so rely on the scents sounds of the individuals to keep the group together when they travel. Each individual herd has a distinctive scent which marks each member of the group and their territory. Though hunted today, no evidence was found in the cliff dwellings to suggest the Salado did or did not hunt javelinas

Mountain Lion

Other Common Names: puma, cougar, catamount (short for cat of the mountains), panther
Scientific Name: FELIDAE, Felis concolor

Description: males weigh up to 200 pounds, females to 100 pounds; total length up to 7 feet; lean body, strong legs, large, round feet with sharp claws, cat-like face, eyes and ears; fur, grayish-brown to light brown in color with white underneath; long round tail with black tip; kittens have spotted fur for the first three months

Habitat: mainly in rugged areas with heavy vegetation including riparian canyons
Diet: primarily deer, but also javelina, bighorn sheep, jack rabbits, porcupines, squirrels, and many other small mammals
Predators: Mountain lions are top of the food chain. They do compete with each other and man for habitat.

Other Information: Once ranging throughout the US, now rarely seen outside the western states. Mountain lions have small hearts and lungs for their size. This allows them to chase for short distances, but forces them to give up if the prey eludes them. They prefer to stalk their prey, pouncing on the animal, either from heights or from close range. Large kills are dragged to a secluded place for dining. Leftovers are covered by dirt and leaves and returned to until finished. Mostly out at night, the mountain lion will hunt during the day if prey is scarce. Between three and five kittens may be born anytime during the year. They stay with the mother for up to one and half years learning how to survive and hunt. The siblings may stay together longer to increase the success of their hunts. Other than these times and during mating, the mountain lions are solitary in nature. A mountain lion’s toe bone was found during excavation. The bone showed no signs of being worked for jewelry or tools. Did the Salado collect this bone? Or, after the Salado left, did one of the many animals using the dwelling collect it?

Ringtail Cat

Other Common Names: miner’s cat, band-tailed cat, civit cat, coon cat, ringtail, bassarisk, cacomixtle
Scientific Name: PROCYONIDAE, Bassariscus astutus

Description: weighs about 1-2 pounds; total length about 30 inches; large ears and pointed nose, small round feet with sharp retractable claws; grayish-brown fur with long bushy tail which is longer than body, tail has about seven black and seven white rings ending with a black tip; large black eyes ringed in white fur

Habitat: cliffs, rocky canyons, thickly vegetated washes
Diet: rodents, fruit, birds, lizards, insects
Predators: Great Horned Owls, bobcats, coyotes

Other Information: Ringtails are nocturnal and rarely seen during the day. Their large eyes and keen sense of smell locate prey in crevices and rocks. They are expert climbers of walls, ledges and trees. Their hind legs rotate 180 degrees for climbing. This even allows them to descend cliffs headfirst. Their long tail balances them as they walk along ledges and branches. Ringtails are fierce fighters, but when frightened, they discourage predators by giving off a musky odor from their scent glands. During June, two to four kits are born. The kits stay with the female ringtail learning to survive and hunt on own. By autumn they separate, living solitary, other than for mating in April. The name, “miner’s cat,” came from early prospectors. They kept them in their cabins to kill the mice. The scientific name means, “clever little fox.” Voted on by students around the state, the ringtail cat was selected as Arizona’s State Mammal.

Riparian Corridor Characteristics at Tonto National Monument

Cave Canyon consists of both wet and dry riparian environments. These areas differ mainly by the amount of water available during the year. As one walks along Cave Canyon, dense tree canopy and green undergrowth around the spring open to shorter, small-leafed trees and brush. Each is a distinctive community. Select a choice to learn more about the differences.





Riparian Corridor Endangerment at Tont National Monument

These riparian communities support the richest diversity of desert life. They are in danger. Desert riparian areas are disappearing, though not as quickly as rain forests. Many factors affect their status. The urban spread of houses and businesses requires water. As this and other development increases, ground water is pumped out to meet water needs. Groundwater levels fall below the reach of deep-rooted desert trees. Trees creating the wet and dry riparian zones die out. Water is closer to the surface in washes and streambeds than in other desert lands. The vegetation changes allow greater erosion of riparian banks. As wash channels and banks are changed, the amount of water flowing out to flood plains decreases. This, in turn, limits absorption of water into groundwater aquifers. Cutting of trees, overgrazing, mining, and recreation also impact the health of riparian habitats. Animals using the riparian corridors are no longer as plentiful as they used to be. Bears and wolves, once frequent visitors in riparian areas, are now rare sights. One species, the Mirriam pocket mouse, has disappeared completely. Is the future safe for Tonto National Monument’s riparian habitats? Only time will tell. Location within the park’s boundaries provides the greatest protection from many of the problems stressing other riparian areas. One potential problem still exists. The watershed above Cave Canyon lies outside park control. Many activities, such as grazing, mining, recreation use, etc., occur within those lands. These uses may affect the health of the riparian habitat downstream. The park continues to monitor these issues with the future in mind. In the end, adding the watershed lands to Tonto National Monument may provide the only solution for Cave Canyon’s total protection.


Riparian Corridor Plants at Tonto National Monument

In Arizona alone, 200 – 400 plant species grow in riparian areas. Most of the plants below require the dependable water source and environment created by the wet riparian zone. Select any the plants to find out more about them.

Arizona Black Walnut

Other Common Names: Arizona walnut, nogal
Scientific Name: JUGLANDACEAE, Juglans major

Description: growing to heights of 50’; forked trunks with rounded crown of spreading branches; grayish-brown bark, rough with ridges and grooves; yellowish green leaves with 9 – 13 lance-shaped leaflets with toothed edges, paired leaflets with single leaflet at the end; blooms early spring, small greenish flowers before and during new leaf development, male and female flowers on the same tree; pollinated female flower produces fruit, hairy brown husk covers nut; nut matures early autumn
Habitat: growing along streams and in canyons; elevations 2,000’ to 7,000’

Other Information: The Arizona black walnut is a deciduous tree normally found in mountain canyons. The lower elevation trees are usually found in waterways that begin in the mountains. Broken walnut shells were found during dwelling excavations. The nuts were probably eaten raw, but it’s also possible they were mashed and mixed with other ingredients.

Arizona Dewberry

Scientific Name: ROSACEAE, Rubus arizonensis

Description: shrubby, prickly plant with trailing branches, flowering branches erect; groups of three green leaves with toothed edges; small white flowers blooming March and April; small dark red fruit ripening April and May

Habitat: grows along streams in partial shade; elevations between 3,500’ and 5,000’, but at Tonto NM the dewberry grows at an elevation of about 2,900’

Other Information: The Arizona dewberry is in the same genus as cultivated blackberries and raspberries. The trailing habit of the dewberry helps protect soil against erosion. Birds and other wild animals eat the fruit. There is no evidence to suggest how the Salado used the dewberry, but the berries are edible for humans. Besides raw, the berries can be cooked for jam and jelly. The dried leaves make a good tea.

Arizona Sycamore

Other Common Names: Plane tree, button-wood
Scientific Name: PLATANACEAE, Platanus wrightii

Description: growing to 80 feet; smooth bark of whitish color; bark at base darker gray and rough; bark peels in brownish flakes; leaves light green on top and paler underneath; small hairs on leaves; leaves look like the palm of the hand with 3-7 pointed finger-like extensions; leaves as big as 10 inches long and wide; blooms March to April; ball like clusters of greenish flowers maturing to tan, hairy round seed-head

Habitat: along stream banks, washes and rocky canyons; elevations between 2000’ and 6000’

Other Information: This is one of the largest trees in the southwest. This deciduous trees provides wonderful autumn colors before losing its leaves in the December. The sycamore’s root system provides a slowing of erosion along stream banks. The flowers are not showy enough to attract pollinators. Wind pollinates the flowers. Small owls and other birds nest in the hollows of old sycamore trunks. The Salado used the sycamore for fuel and construction.


Other Common Names: elder, sweet elder, boretree
Scientific Name: CAPRIFOLIACEAE, Sambucus sp.

Description: grows as shrub or small tree to 20’ in height; brown or gray bark with ridges and grooves; dark green leaves with 4-8 leaflets paired opposite each other and one leaflet at the point, leaflets oval-shaped and saw-toothed; blooms March - June, small yellow to white fragrant flowers in large flat-topped clusters; berries dark blue with white powdery coating

Habitat: stream sides and canyons

Other Information: Deer eat the leaves; birds eat the berries. Not all varieties of elderberry are edible. The berrries are used for wine, jelly and pies. The fruit can be dried for future uses. The bark has been know for fever medicine.

Miner’s Lettuce

Other Common Names: Indian lettuce, Spanish lettuce
Scientific Name: PORTULACA, Claytonia perfoliata

Description: stems rise from a bunch of basal leaves; dark green fleshy leaves, some lance shaped; flower bearing leaf surrounds the stem; blooms February through May; tiny white to pinkish blooms rise above the center of the leaf

Habitat: along brooks and around springs, moist places in shade; elevations 2,500’ to 7,500’

Other Information: Perfoliata means the stem perforates the leaf. Leaves, stems and roots are edible raw or cooked. The name, “miner’s lettuce,” comes from the miners in the early gold rush days of California. Fresh fruits and vegetables were difficult to come by. They relied on this and other plants to provide the Vitamin C needed to prevent scurvy and other diseases. The other names suggest the miners learned about this edible plant from local Indians or Spaniards.

Netleaf Hackberry

Other Common Names: sugarberry, western hackberry, false elm, palo blanco
Scientific Name: ULMACEAE, Celtis reticulata

Description: grows in height of 20-30’, short trunk with open leaf canopy; bark gray and smooth, but becomes rough with crevices and warts as it ages; leaves dark green on top, yellow with veins underneath; two rows of leaves oval-shaped with saw-toothed edges; small greenish flowers blooming April to May; small orange to red berries with one seed mature in late autumn

Habitat: canyons, washes, stream sides and springs; usually between 1500’ and 6000’ in elevation

Other Information: Hackberry trees are deciduous and add yellow color to the desert before loosing their leaves in late autumn or early winter. Fruit hangs on the tree all winter providing many birds with food. They eat the fruit whole. Seeds pass through their system without being damaged. As long as the conditions are right, the carried seed has a chance to grow far from its origins. Rounded galls, a swelling of plant tissue, form on the leaves due to tiny plant lice. Some galls are an important source of tannin, a substance used in tanning, dyeing, the making of ink, and medicine. It is unknown if this is true of the netleaf hackberry’s galls. Salado probably ate the fruit. The pits or seeds were found in excavations of the dwellings. This may indicate that the berries were eaten fresh. They may have dried the berries, then ground the whole fruit, including seed, into flour. A bow found in excavations was made from the wood of the hackberry. Other possible uses of the wood include tool handles, digging sticks and fuel.

Wild Cucumber

Other Common Names: gila manroot; big-root
Scientific Name: CUCURBITACEAE, Marah gilensis

Description: vine, using shrubs and small trees to climb on, attaching with tendrils; leaves are dark green with pointy or rounded lobes to 3” wide; blooms March to April; small, white, star-shaped flowers about ¾” in diameter; round, green, fleshy fruit about 2” in diameter with stout smooth spines of irregular lengths

Habitat: thickets around washes and streams; below 5000’ in elevation

Other Information: By the beginning of the dry season, the vine dies back to its large, tuber-like root. New vines grow each year from the root. Growth appears as early as March, but are killed by freezing temperatures. Is it edible? The fruit is not edible. Many plants known as wild cucumber are poisonous. The tuber-root of one closely related species is edible. Documentation about the Marah gilensis is limited. It is unknown whether the Salado used this plant as a food source.


Riparian Corridor Research at Tonto National Monument

How do we know what animals live or travel through the park? Since riparian areas support the vast majority of desert wildlife sometime during their life cycle, Cave Canyon is a research area. Biologists, along with park personnel, document the presence of plants and animals through collection of evidence. Animal tracks, hair fibers, scat and other physical remains are one source of information. Various types of cameras are commonly used. Shy of human activity or nocturnal in nature some animals trip a camera shutter in the riparian corridor. Film permanently records their presence for all to see. Scientists and staff also take pictures of Gila monsters’ coloration patterns. They are seen more often in the riparian area than in other areas of the park. This is the first stage of recording this unique identifier. One tool not commonly used is the audio recorder. The riparian area is one of several sites in the park where bat sounds are recorded for research. They hope to learn more about the relationships of the sounds to the different species of bats.

Live trapping of small mammals and bats helps identify species within the park. Researchers gather information on health status, size, weight and other concerns before releasing the animal. One researcher captures snakes to either install radio transmitters or pit-tags. The radio transmitters track rattlesnakes to determine their travel habits. A hand-held barcode reader scans those snakes with pit-tags for their identifying number. The capture and release locations, including time of day, are recorded. Knowledge of why a snake goes where it goes is important. The ultimate goal is to limit snake encounters on trails and in park housing areas. The possibility is present of changing human behavior to change snake behavior.

Researchers arrive throughout the year to check on seasonal status of a specific animal. Others are identifying species present during certain seasons. This is especially true of birds. Many birds use the riparian area to rest in their migratory journeys. They enjoy the available insects and fruit. All this gathered information assists Tonto National Monument’s task of protecting the natural resources for future generations.


Stop #6 – Mesquite

Mesquite trees are rich with interdependent life, a protected place with shade, moisture and nutrients. The trees line dry washes, exist as individual trees or grow together to form small forests. The trees and the area around them are alive with many plants and animals. The tree canopy provides shelter for birds. Mammals also enjoy the shelter under the canopy, especially in the summer. Twice the number of fleshy stemmed plants grows under mesquite shelters as in the spaces between the trees. Well over a million flowers rich in pollen and nectar are produced each year drawing many insects and their predators. Seedpods are an important food source for many wildlife species, including insects. Larger mammals support the trees by eating the pods. Seeds passing through the animals are more likely to germinate, in part because the digestive juices kill seed eating bugs. Otherwise, a few years of weathering is needed to release the seeds from the endocarp and start new trees. Smaller mammals gather and store the seedpods, sometimes scratching the seeds in the process, which also begins the mesquite growth process. Packrats are one such animal. They collect the pods, carefully sort them from other seeds and store them in their middens. In lean years, when their own harvest was used up, native people knew to collect the pods hoarded by the packrats. Mesquite trees are an important part of the desert environment.

Benefits of Mesquite

Despite the critics, there are advantages from mesquite. These trees have nitrogen-fixing bacteria among their roots. This is a symbiotic relationship. The mesquite provides carbon and good habitat for bacteria. Bacteria in turn, converts nitrogen of decaying material into nitrate that plants can use. Mesquites have higher amounts of nitrogen compounds in their tissues. When their leaves decompose, they release nitrogen and enrich the soil. The trees are self-fertilizing and as the tree ages the soil beneath the tree grows richer. Some native people line their fields with mesquite trees. During thunderstorms, the nitrogen rich mesquite debris is washed down to other areas to enrich the soil for farmlands or other plant productivity. Nitrogen is an essential element in proteins. Nitrogen-fixing plants can make large crops of seeds with high protein contents. Mesquite sometimes develops two crops in a year. Besides being rich in nutrients, the pods have been proven to help control bloods sugar. Some foods made with mesquite pods do not need to be cooked, saving fuel. The wood is currently chopped and burned to create charcoal for the food industry’s mesquite flavoring. Burning dried mesquite pod would do the same thing. With over a million flowers per tree per flowering, the bees go crazy collecting nectar to produce a wonderful honey.

Consider the many other ways people have used mesquite. Could these trees, still considered pests, be used for economic opportunities? What mesquite products and businesses do you think are possible? Bee keeping? Medical research? Fertilizer? Food products? Others?

Life in the Mesquite

Mesquite trees and all their parts support animals and other plants. Some of the animals provide benefits to the mesquite, while others do not.

Honey Bee

Other Common Names: European honey bee (EHB), Western honey bee
Scientific Name: HYMENOPTERA, Apis mellifera

Description: drone - 5/8 inches in length; queen - ¾ inches in length; worker - 3/8 to 5/8 inches in length; all – pale erect hair mostly on brown thorax, black and orange banded abdomen, short translucent wings; blackish head, antennae and legs

Habitat: open areas, nesting in tree holes, rocks and crevices
Diet: flower nectar, pollen (protein source)
Predators: parasitic mites, several bird species, raccoons, skunks, lizards, javalina, coatamundi, bears, waxmoths, spiders

Other Information: The honey bee plays an important role in pollination, especially of crops. Europeans brought these bees to the Americas in the 1600s. The Salado would not have seen these bees in their time. The bees were a combination of German and Spanish varieties. Over time, they were bred for gentleness and honey production. Bees escaped from the managed hives and became part of ecosystems throughout America. Within the colony, three kinds of honey bees exist, each with their own special role. The queen bee lays eggs and rules the hive with chemical messages called pheromones. The worker bee, a sterile female, does all the work the hive requires, including collecting pollen and nectar and caring for the eggs. She has a pollen basket on her hind legs to store the pollen collected on body hairs. The workers locate flowers through vision, seeing colors ranging from ultraviolet to orange, but not red. The drone or male serves only to fertilize the queen then dies afterwards. Unmated males die too, since the workers no longer feed them when food sources are scarce. As new possible queens emerge in the hive, the old queen heads out with a swarm of workers to find a new home. This swarm is less likely to attack since they do not have a home to protect. Weather, season and food availability can affect the mood of any bee colony, but they are not particularly aggressive. They don’t usually sting unless they feel the hive is threatened or other bees are killed. Injured or stinging bees release a pheromone that stimulates other bees to attack. Meanwhile, back at the old hive the first queen to emerge kills off any other queens and begins the cycle again. They occupy the same nest year after year, storing honey to see them through cold winters. Water regulates the hive temperature, so the colony is usually located within one mile of water. During flowering time, their focus is on honey production. They usually forage within one mile of the colony, but may go a maximum of eight miles. Besides producing a superior honey from mesquite, the bees are more productive. With so many flowers together, the bees can collect a lot of nectar in one trip. How do these relate to Africanized honey bees?

Africanized Honey Bee (AHB)

European honey bees and African honey bees are members of the same species, but evolved under different environmental conditions. European honey bees had long, cold winters and intense nectar flows of relatively short periods. They learned to store their resources for times of shortage. The honey bees of Africa had an annual pattern of wet and dry seasons and weak, unpredictable nectar flows. They learned to use their resources to raise more bees. In 1957, African honey bees were imported to Brazil to see if they were better suited for the tropical conditions. Some of the African bee swarms escaped into the countryside and interbred in the wild with European honey bees (EHB), resulting in the new hybrid, Africanized honey bee (AHB). Their differences are not easily seen. A microscope is needed for true identification. With the AHB concentration on reproduction, they can quickly outnumber the EHB in an area. AHB has a shorter egg to adult development time. The have to work harder to provide for more young, so may even be out when the moon is bright foraging for nectar and pollen. One nest can produce 60 new colonies per year under the best conditions. This means they swarm more often as they look for new homes. EHB produce no more than three new colonies per year. AHB are known to defend their nest more quickly and to pursue intruders for longer distances. When the pheromone signals, three to four times as many workers respond to the threat. It also takes much longer for the hive to calm down. Venom from an AHB sting is no more potent than an EHB sting. With their suitability for warmer climates, the Africanized honey bee has spread to the southwestern United States. Only time will tell of their impact on the environment and the environment’s impact on them.

Bruchid Beetle

Other Common Names: Seed-feeding mesquite beetles, seed-beetles, seed weevils
Scientific Name: BRUCHIDAE, Algarobius prosopis

Description: up to 5 millimeters in length; egg-shaped body; light brown color with hardened fore wings darker than rest of body; abdomen extends beyond the fore wings

Habitat: mesquite trees
Diet: adults -- mesquite flowers; larvae -- mesquite seeds
Predators: insect eaters; as a by-product of eating the seedpods, the digestive juices of mammals and other vertebrates kill the larva and pupa

Other Information: The bruchid beetle is a natural enemy of mesquite through destruction of its seeds. It lays eggs in cracks and blemishes on the seedpods. Each grub or beetle larva burrows into the pod and seed, destroying one seed. The pupation, middle stage in the cycle, happens in the hollowed out seed. The adult, last stage of the cycle emerges through the neat, round hole on the surface of the pod. The seeds are destroyed whether in the tree and on the ground. It also infests stored seeds. Up to 95% of a season’s seeds may be destroyed through this continuing cycle. However, invasions are limited through animals using the pods as a food source. In some places, the beetle has been introduced in an attempt to naturally control the spread of mesquite.

Desert Mistletoe

Other Common Names: mesquite mistletoe, American mistletoe, “the slow killer”
Scientific Name: Phoradendron califonicum

Description: dense clusters to 2 feet in diameter; brittle jointed stems with scale-like “leaf”, spring flowers of yellowish-green not easily seen, but very fragrant; small round berries ripen to red in winter

Habitat: deserts and foothills growing mostly on legume trees and shrubs; mesquite main host

Other Information: Mistletoe is an evergreen plant and only a partial parasite. The roots invade the bark and sap to absorb water and nutrients from its host plant, often killing the host. Mistletoe has its own chlorophyll, so is able to do its own photosynthesis. Though not showy, the flowers attract bees and other insects for pollination. This is important because there are separate male and female plants. Only the female plants produce berries. The berries are sweet when growing on most legumes, but bitter when growing on palo verde and non-legume plants. Besides edible berries, a medicinal tea is made from the stems or from the berries. A wash for sores could be also made from soaking the stems in warm water. Be careful! Most mistletoe plants are poisonous.

Ladder-backed Woodpecker

Scientific Name: PICIDAE, Picoides scalaris

Description: up to 7.5 inches in length; chisel-shaped beaks; short legs with strong toes and sharp claws; black and white bars on back like ladder rungs, cream underneath with black side spots, black and white strips on face, red cap on male, black cap on female

Habitat: wooded desert washes; woods in foothills; elevations to 4500 feet
Diet: insects, cactus fruit
Predators: raptors such as hawks

Other Information: The ladder-backed is a small woodpecker. Its strong head and neck muscles, strong toes, sharp claws and stiff tail feathers help keep it secure and upright on vertical surfaces. A woodpecker’s skull is adapted to absorb the shock of driving its beak into trees. It has a long tongue with a bristled, sticky tip to lap up insects. Four to five white eggs are laid in nests built in mesquite, oak or willow holes. Sometimes nests are in the stalk of agave or saguaro. Besides eating bugs in the bark of the mesquite, they also help the agave. After pollinating the flowers of the agave, the agave beetle lays its eggs in the flower stalks. The ladder-backed woodpeckers eat the seed-eating beetle larvae. This limits the population of the beetle and the destruction they cause.


Other Common Names: silky flycatcher
Scientific Name: PTILOGONATIDAE, Phainopepla nitens

Description: up to 8 inches in length; thin bill, long tail, head crest, red eyes, male – glossy black with white wing patch only showing in flight, female and juvenile – gray with pale wing patch showing in flight

Habitat: mesquite trees along washes, tall trees along rivers
Diet: mistletoe berries, other berries such as elderberry, insects
Predators: raptors such as hawks

Other Information: Phainopepla (fay no PEP la) means, “shining robe” in Greek. The silky-flycatcher name comes from their flight to catch a mouthful of insects. They arrive at Tonto National Monument with the ripening of the mistletoe berries and depart when the mistletoe and other berries are gone. February to April is breeding season with shallow nests in mistletoe bearing trees, like mesquite. Two to four greenish speckled eggs are laid with a possible second nesting occurring during a summer residence in oak and sycamore canyons. They defend their feeding territory when the berries are plentiful, but at other times, only guard their nesting tree. An old nest may be indicated, hidden by a new growth of mistletoe. They wipe the sticky seeds of mistletoe berries on branches to clean their beaks or leave droppings on host plants. If the seeds find a good spot, the phainopepla has “planted” more food for the future.

Reakirt’s Blue Butterfly

Other Common Names: Solitary Blue, Mexican Blue
Scientific Name: LYCAENIDAE, Hemiargus isola

Description: butterfly -- small about ¾ - 1 inch; white fringes; fore wing undersides have black spots ringed with white; male - light blue wings with slightly darker veins and 1-3 margin spots on hind wing, female - similar but darker; caterpillar – average length about 1/2 inch; light green and marked with red

Habitat: open areas at lower elevations such as deserts, grasslands, meadows and abandoned fields
Diet: caterpillars eat flowers and seedpods, sometimes leaves of many legumes such as mesquite; adults eat flower nectar from a variety of herbs
Predators: insect eaters

Other Information: Reakirt’s Blue butterflies are members of the gossamer wing family. The family’s iridescence is the result of light bouncing off their wing scales. Wintering in the south, The Reakirt’s Blues migrate north for the summer. Adults are seen flying from March to November. Females lay their eggs on the host’s flower buds. The new larva or caterpillar secretes a sugary solution attractive to different species of ants. If there isn’t an ant’s nest already beneath the tree, a caterpillar produced vibration travels through the plant to call to the ants. These ants obtain nutrients from the larva and in turn protect it from predators and parasites. When threatened, the caterpillar can produce a scent, driving the ants in a frenzy to scare away the potential threat. As the caterpillar grows it sheds its skin to allow the growth. After the last shedding it finds the nest of one of the different protective ant species, crawling down there to make its transformation into a butterfly. After the transformation, it only has two minutes to exit the nest or be killed by the ants, as the adult butterfly does not secrete the solution.

Rock Squirrel

Scientific Name: RODENTIA, Spermophilus variegatus

Description: up to 20 inches in length; up to 1.5 pounds in weight; small ears; sharp teeth; strong claws; fur -- gray or grayish-brown speckled with black and tan, light-colored under belly; up to 9 inches long bushy tail with black tip, whitish eye ring

Habitat: burrows and nests in and among the rock piles, rocky outcrops and canyon walls
Diet: mesquite new leaves, flower buds and seed pods, palo verde seed pods, black walnut, cactus fruits, grass seeds, eggs, young birds, insects, carrion, other fruits, berries and seeds
Predators: hawks, roadrunners, coyotes, snakes and other predators

Other Information: Rock squirrels are one of the many rodents living within the monument. Two important features of rodents help them survive. Their incisors or front teeth continue to grow throughout their lives. Otherwise, the way they gnaw on things would wear the teeth away. Their eyes are high on their head so they can see danger for a wider area. Rock squirrels sound a shrill whistle to warn others of danger. Rock squirrels live alone or in colonies among rocks. They search on the ground for food, but will climb mesquite and other trees for food. They also climb the agave flower stalks to gnaw on the tender stalk or to eat the seedpods. They are not active during the coldest months. It is unsure whether they hibernate since they will come out on warmer days to sun. Five to ten young are born in early spring with sometimes a second litter born in late summer or early fall.

Velvet Mesquite

Other Common Names: common mesquite, algaroba
Scientific Name: Prosopis velutina

Description: large shrub, or tree to 20 feet or more in height; trunk with dark brown, rough bark; twigs of light brown covered in fine hairs and having pairs of spines to 1 inch in length at nodes; yellow-green leaves up to 6 inches long with 15-20 pairs of ¼ to ½ inch leaflets; many small, light yellow, fragrant flowers in narrow clusters to 4 inches in length bloom in April, sometimes blooming again in August; fruit of narrow pods to 8 inches in length ripening in summer, but not splitting open.
Habitat: desert washes; along streams; other places where water table is high enough for roots to reach; below 5,000 feet in elevation

Other Information: The velvet name comes from the fine or “velvety” hairs growing on the leaves, twigs and pods. Mesquite is part of the legume family. Due to the seedpod structure, the mesquite is not a true legume, but remains in the family due to the flower structure. Pods consist of three parts -- woody capsule enclosing seeds (endocarp); between thin skin (exocarp) and endocarp is mesocarp, a mealy pulp. Sometimes a second blooming occurs in the summer after enough rain has fallen with a second crop of pods resulting. In the autumn, bright green leaves fade to dull green and drop off, fulfilling its deciduous designation.

White-tailed Deer

Scientific Name: CERVIDAE, Odocoileus virginianus

Description: up to 6 feet in length; weight to 100 pounds; gray-brown in winter, reddish brown in summer; white belly and inner hind legs; long thick tail gray to brown on top with white edging and underneath; large ears with gray on back and white on inner surface; white around nose, eye and throat; antlers on males, main stem curved forward with tines branching off; first two months fawn reddish orange with white spots

Habitat: desert scrub, broadleaf and mixed woodlands and edges, shrubs, fields and watersides
Diet: leaves and twigs of trees and bushes, grasses and herbs, mesquite and catclaw acacia seedpods, hackberry and other fruits
Predators: mountain lions, bobcats, coyotes, golden eagles, feral dogs, humans; young also killed by gray foxes, owls and hawks

Other Information: White-tailed deer browse grassland slopes above Cave Canyon, coming down to the spring to drink during dry months. They are very cautious, looking about frequently as they eat or come to water. The caution is well founded since about half of fawns do not live beyond the first year. Part of a white-tailed deer’s defense is to run. It tells others of danger by curling its white tail up as it flees. They also communicate by stamping, striking their foot on the ground, and by pumping their heads up and down. Their digestive system is made for danger with its four stomach chambers. The quickly swallowed food is temporarily stored in the first chamber. The second chamber shapes pellets of partially digested plant fibers or cud. Once at rest, the cud comes back to the deer’s mouth to be chewed into pulp, swallowed and passed through all four chambers of the stomach in digestion. Mating occurs in autumn and one to two fawns are born in late spring. Males from two years on grow antlers through spring and summer. Soft and tender, the antlers are covered with a soft, fine-haired skin or velvet. The bone growing beneath the skin is nourished by the blood vessels within the skin until reaching full size. The velvet then dries and sheds. The antlers are used to attract females and to battle with other males during courtship. After mating, antlers fall off and the process soon begins again. The antlers are more a health indicator for deer habitat than a sign of age. Each year, as long as the buck has enough food, the antlers become larger and have more points.

More About Mesquite

Over 10,000 years ago, mesquite trees covered the flood plains with bosques (BOSE kays), meaning "small forests" in Spanish. They provided food for the ground sloths and mastodons. As these large mammals died off, the mesquite died off, retreating to washes and waterways. Did it also indicate a decrease in the amount of moisture available to the trees? Though living in a desert, these trees are not drought tolerant. Besides the small leaf structure, which prevents moisture loss and overheating, their root system helps them survive. Mesquite roots grow deep underground for available moisture. The deepest root was discovered over 160 feet below ground in a mineshaft. Not all their roots are that long. A majority of their roots are still within the top three feet of soil, spreading out beyond the edges of the canopy. This is the area of highest moisture and oxygen levels. Still, it requires about a half-inch of rain to wet the deeper root zones. Once wet, the soil stays moist longer, supporting the tree for longer periods of time. This might work for temporary dry periods, but is not a good long-term survival strategy. As the water table drops far below the root structure, the tree dies. However, deep root structure does allow the mesquite to produce a crop even in dry years when most plants do not produce anything. Trees growing away from reliable waterways are short with less leaf canopy, more like a shrub. With enough moisture, mesquite trees live to be several centuries old. What stories would they tell?

Problems of Mesquite

Mesquite goes through ups and downs of use and eradication in the many places it grows around the world. Trees growing with space in between are beneficial. Dense thickets of mesquite cut out light and water to other plants. Mesquite is a hard wood and slow burning and with only clumps of grass, fires are not easily carried by the trees. The thickets become unmanageable without human intervention. Whereas many early people planned where they were living according to the availability to mesquite, many pioneers and ranchers thought they were an invasive pest and worked to get rid of them. They didn’t understand the mesquite and thus became the cause of the problem. Mesquite trees increased rapidly on overgrazed lands. Cows and horses ate the pods in the summer when other grasses had died off. A higher germination rate occurs if the seeds pass through guts of large mammals. Lots of cows mean lots of large mammals to help germinate seeds. Diets high in mesquite pods sometimes killed these domestic animals.

Destruction of mesquite colonies occurred in some places without conscious thought. Early Arizona mining companies devastated the landscape as they cut down thousands of trees to fuel their operations. Even now, trees are killed as groundwater is pumped out, dropping levels below the reach of the mesquite’s roots. For over a century, ranchers worked to rid themselves of the pest, sometimes paying a lot of money. Cutting down didn’t work as new sprouts grew from the old trunk. Dragging chains over, pouring diesel oil on the trunks, setting the trees on fire, using chemicals and pesticides were all tried without much success. Concern grew over the health of people and wildlife with the use of strong pesticides. The direction is now to use the natural enemy of mesquite, the bruchid beetle, to limit the spread of mesquite. Considering the benefits of the mesquite, how much should be destroyed?

Uses of Mesquite

The obvious use for mesquite, as with most trees, is for fuel and building materials. Mesquite, though, is a multi-purpose tree, serving as food store, drugstore, hardware store and occasionally department store. Learn more about its uses from pre-historic times to current day times.


For the Salado, the mesquite was an important resource. Some suggest that prehistoric people selected living sites based on the availability of mesquite. The seedpods were probably their most important food source. During wet summers a second crop of seedpods grows. The seedpods and beans are rich in protein, calcium and iron. They didn’t require cooking to eat, just grinding and shaping into cakes. During excavations, seeds and pods were found. The tough fibrous casings of the seeds were left. Some of the remains were the pods themselves. In one place, mesquite beans were cached as if waiting for the return of the Salado. They may have roasted the seedpods as some seeds and pods showed evidence of being charred. The Salado also used the wood. A t-shaped pendant with a hole at one end was found during excavations. A club of mesquite, possibly a war club, was also discovered. Wood may have been used for fires as mesquite produces more heat than the same amount of pine or juniper.

The Salado may have used mesquite for more things than evidence supports. For some possibilities, check out how other people are known to use mesquite.

Other People

Many uses of the mesquite have been documented. All parts of the tree were used for various purposes. The sweet pods have a slight taste of chocolate or caramel. It easily makes sense when one knows that carob trees are also legumes, the pods used to make a chocolate substitute. The pods of the mesquite are rich in calcium, magnesium, potassium, iron, zinc, protein, lysine and dietary fiber. Research has shown the consumption of the pods is effective in controlling blood sugar levels.


Stop # 7 – Geology

Arizona is a highly active geologic region. Almost constant activity took place from the beginning of geologic history to current times. Four events are most important here. The first one began over a billion years ago. Layer upon layer of silt, sand, mud and other sediments built up and then consolidated into rock. The rock layers created the members of the Apache Group -- Pioneer Formation, Barnes Conglomerate, Dripping Spring Quartzite and Mescal Limestone.

Between eight and fifteen million years ago, the second event uplifted the Apache Group and the layers above it. This upheaval created deep basins and high mountain ranges. Mountain debris filled basins as erosion followed uplift. Moisture within the debris evaporated. Remaining minerals cemented the debris together to create Gila Conglomerate.

Less than a million years ago, another event of uplift and erosion occurred. The youngest rock members of the Apache Group became the mountaintops. The Salt River cut a deep channel in the basin and carried much of the old debris away. Gila Conglomerate remained in the lower basin, coating the face of the Apache Group.

The final event began between 400,000 and 50,000 years ago. Water seeping down through the rock layers dissolved natural cement and cave formation began.

Those are the geologic events preserved here. The Apache Group forms the mountains of the Monument with Roosevelt Lake lying in the basin below. Rocks of Gila Conglomerate are everywhere, especially on the cliff face of the Dripping Springs Quartzite. The cliff dwellings sheltered within the caves, which formed in the Dripping Springs Quartzite layer. An incomplete picture of geologic history exists here, for the rock layers of the highest cliffs here and the lowest cliffs of the Grand Canyon date to about the same age.

Timeline Introduction

Over the years, geologists worked as rock detectives to date the layers and features of Earth. They studied the thickness and structure of rock layers for clues to how they formed. Sometimes faults, folds and injections of molten rock changed the layers. The detectives searched for a complete picture in other locations with unchanged layers. The study of fossils buried within the layers also provided clues to the age of rocks. As technology advanced, tests supplied more exact dating. Still, the farther back in time, the less precise layers are dated. The timeline represents the most current knowledge of time and events creating the landscape features in and around Tonto National Monument.

Today into the Future

Weathering and erosion are continuing forces of change in the Monument’s landscape of today and tomorrow. Occasional rockslides occur. Flash floods alternately scour and fill the washes with debris.

Cenozoic From the present to about 65 million years ago

A natural process called spalling formed the caves, probably starting between 400,000 and 50,000 years ago. The rock alcoves that house the cliff dwellings are located in a layer consisting primarily of siltstone. Water dissolved the minerals binding the rocks together. Layers of siltstone break loose and fall from the ceiling.

Less than one million years ago, all of central Arizona was gently uplifted as much as 4,000 feet. A new cycle of erosion began, continuing to the present day. Major stream systems, including the Salt River, developed. They removed accumulations of Gila conglomerate leaving some cemented to the face of the cliffs. The valley deepened as the Salt River carried away basin debris faster than eroding mountains deposited new debris. The basins deepened, as debris no longer collected.

About 8 to 15 million years ago, this area experienced a period of great change. Rocks broke, some segments rose, others dropped or tilted. This evolution created the foundation for the present landscape. Uplift and tilting crudely defined the shape of land. Debris filled the basins from highland erosion. Swift rivers carried gravel to low areas for deposit. Gila conglomerate formed as gravel accumulated to tremendous thickness in centers of major basins and covered or nearly covered most of lower mountains. Minor volcanic activity sometimes accompanied deposition of Gila conglomerate as indicated by a few basalt flows layered within the gravel.

Toward end of Mesozoic and beginning of Cenozoic Eras, tremendous forces were at work. Mountains were uplifted, folded and faulted with intrusions of molten rock, some rich in copper and other minerals. Huge blocks of rock were raised or dropped. Erosion cut down high rugged mountain ranges and destroyed the sedimentary layers deposited during the Paleozoic and Mesozoic Eras or previous 475 million years. Copper mining in nearby areas is the only evidence of this work.

Mesozoic About 550 About 248 - 65 million years ago

This area became part of an ancient desert with wind swept and drifting sand dunes much like the Sahara Desert. (destroyed in next event)

Paleozoic About 540 - 248 million years ago

This area was again invaded by sea. Sedimentary layers were deposited on top of the Apache Group. At times, areas of land were lifted above the sea. Sands and silts of river flood plains and deltas were deposited. During periods when seas withdrew, erosion was at work. (destroyed in event after next)

Precambrian About 1 billion – 540 thousand years ago

Any evidence of the geological events occurring during this period disappeared during the long episode of erosion at the end.

About 1.5 - 1 billion years ago

The sea invaded the plains, forming the member layers of the Apache Group – Pioneer Formation, Barnes Conglomerate, Dripping Spring Quartzite Formation, and Mescal Limestone Formation. Many layers of siltstone, sandstone, mudstone and limestone were deposited near the shore as the sea deepened. Thin basalt flows covered the top of the Apache Group from nearby volcanic activity along with fine-grained volcanic debris embedded in layers. Molten rock or diabase was forced into fractures within the Apache group creating dikes - vertical structure of volcanic rock - and sills - horizontal structures of volcanic rock.

About 2 billion years ago

This period created an ever-changing landscape – thick deposits of sediments and volcanic rock were left as the sea invaded and withdrew; uplift, folding and faulting built mountains; and finally the mountains were eroded away to almost featureless plains. Any of this rock lies deep below the surface of the Monument. (no names for the formations and I don’t know of any place to see them. I’ll see what I can find)

Rock Types

Rock features help to tell a story. Most of the rock in and around the Monument is sedimentary. These rocks formed from the remains of older rocks. Wind and water deposited the rock sediments in other locations. Pressure or minerals within the layers converted the sediments to rocks. Many rocks along the cliff dwelling trails and in the dwellings tell more about the deposition environment. Some display features formed in shallow water or on tidal flats. Other features tell of wind and water erosion shaping rocks.


This earliest form of visible life grew in tidal flats of shallow seas. Sand, silt or mud covered mats of blue-green algae. The algae cemented the sediments down, then began the next layer. These layers created coral-type formations. Through time, this life became the oldest known fossils and the only fossils found at Tonto National Monument. This remainder of ancient life still lives and grows in Australia, surviving only because environmental conditions are just right.

Stalactites, Stalagmites and Columns

As water traveled through the rocks dissolving sediments for cave formation, it picked up calcite. Water does not dissolve this mineral and carries it along until deposited in other places. The water left calcite formations as it dripped from the cave roof or passed across the surface of the rocks. Stalactites hang “tight” to the ceiling of the cave. Stalagmites “might” grow up to be stalactites. Columns form where stalactites and stalagmites met. Small formations of stalactites, stalagmites and columns are visible in the caves of the cliff dwellings.

Barnes Conglomerate

A conglomerate indicates eroded material moved and sorted by water. Minerals within the deposit create natural cement, developing a new rock or rock layer. The composition of the material within the conglomerate usually indicates how far the material traveled. The larger the rocks, the shorter the distance traveled. The more rounded the rocks, the longer the distance. The greater the uniformity of the material size, the farther the material traveled. The Barnes Conglomerate consists of rounded, water-worn pebbles of older rock, but the varying size indicates they did not travel far. Some of these pebbles include quartzite, white vein quartz, jasper and volcanic rocks. Eroded sand particles of feldspar-rich arkose create the pinkish color of the cement holding the pebbles together. Barnes Conglomerate is one of the older rock layers of the Apache Group. Most of it lies below the surface. The wash in Cave Canyon cuts deep enough to expose a section of this rock layer.

Mud Cracks

Mud cracks strongly indicate layers deposited in streams, puddles and shallow sheets of water, like tidal flats. Alternating wet and dry conditions created the cracks. In times long ago, sediment of the next layer filled in the cracks. This created ridged patterns of cracks criss-crossing the base of the new layer. When the layers separate, the evidence is visible in the rocks, both in the indents of the lower layer and the ridges of the upper layer.


Sediments settling in still water leave no features on the top of the layer. Waves and water currents create ripples of alternating ridges and troughs on the layer’s surface. Sometimes sedimentary rocks preserved these ripples. Geologists can tell the direction of the depositing current by the ripple marks. Here, the size and location of ripple rocks would not help any rock detectives in their search for clues.

Salado and Geology

To some, geology is a matter of pretty rocks and scenic views. To the Salado of Tonto National Monument, geology created the shallow caves sheltering their cliff dwellings and the productive river basin for their farming needs. It provided the building blocks for dwellings and terraces. Geology created the raw material to mortar walls, to shape tools and to create pottery. It was a resource to decorate their lives.

They used stones for a variety of tools. Most used for what is now done by metal tools. They used stoned axes alternating with fire to cut trees. The axes also broke up the soil and rocks while digging irrigation canals. They attached handles to stone mescal knives and cut agave during harvest. Deep grooves developed in shaft straighteners as they prepared arrow shafts for use. Stone scrapers prepared plant fibers and animal hides. Manos and metates ground seeds and other types of food. Some stones even worked as multipurpose tools. Shaped or unshaped, there was a tool for every task.

There were so many possibilities for the rocks and so many available in the area. Trade brought rock types not locally available. Colors and patterns added something more to the utilitarian tools. Color and carving created ornaments for wearing. Were the prettier stones worth more? Was it someone's daily task to shape and sharpen stones?


Stop #8 – Among the Saguaros

Early explorers thought the saguaro was an odd type of tree. Though part of the cactus family, large groups of saguaros are called forests. The saguaro takes on the role of a tree as part of a unique ecosystem, interconnecting plants and animals. Early human occupants of the Sonoran Desert also became part of the web of life revolving around the saguaro. For all, the saguaro provided of food, shelter and moisture in an arid land.

Humans are now creating problems for the saguaro and the animals relying on it. Shooting and throwing rocks for fun damages and sometimes kills saguaros. Wildfires from careless human acts burn not only saguaros, but also habitat needed for reproduction. Cactus rustling is big business. Protected by law, all cacti require permits for taking them from public lands. Transplanting a saguaro is not highly successful. It may only survive another ten years before dying. Left in the desert, it may have lived another 100 years. Human influence may decrease future populations of saguaros more than natural causes. Tonto National Monument is one of many places where saguaros have a chance to evolve naturally, insuring their availability for future generations of animals and humans.


Humans have lived longer in southern Arizona than saguaros. Oral traditions of the Seri and Tohono O'odham cultures tell the beginning of saguaros. The stories tell of humans becoming saguaros and the importance of proper respect for the saguaro. It is not surprising that these cacti take on human form with their arms and distinctive features. What stories would old saguaros tell of their early years, when the United States was young and human thoughts were turning to exploration of this vast land? "I remember when I was about ten feet tall…" "I remember the first time I grew an arm…"

Humans once lived in harmony with the saguaro. The beginning of Tohono O'odham year revolved around harvesting the saguaro fruit. Coming after a month of food scarcity, the fruit provided moisture and food in the dry time before the monsoon rains. The fruit contains 10-26% protein and 70% carbohydrates. The seeds are rich in fat and protein. With the opening of the first fruit, gatherers would stop for a blessing to thank the fruit for its existence and ask it for another year of harvest. Wine produced with the fruit became part of the ceremony to bring on summer rains. They also respected the rights of animals to use the saguaro and its fruit. For the Salado, evidence suggests only the physical relationship to the saguaro. Was the saguaro an integral part of their life? Or, were other plants more important?




Woody Ribs




Many different species of mammals, reptiles, birds and insects use the saguaro for food, shelter, and/or moisture. From the top of its stem and arms to the roots below, a city of sorts exists. Some of its residents are transient; others live from birth to death in and around the same saguaro. Some only use the food and water resources in their travels. Activity in and around a saguaro changes with the seasons of the year and throughout the its lifetime.

Saguaros provide both a direct and indirect source of food. Many animals take advantage of flower and fruit seasons. As they eat the pollen and nectar, birds and insects help pollinate the flowers. The fruit provides moisture in the dry time before summer rains begin. The insects and birds able to reach the heights of the saguaro enjoy the mature fruit pulp and seeds first. Once on the ground, mammals such as woodrats, coyotes and even desert bighorn sheep eat the fruit. Not all herbivores are able to eat the fruit. As animals take advantage of these food sources, their predators take advantage of them.

Others prey upon the animals living in and around the saguaro. Raptors, like red-tailed hawks, use the tops of the saguaros to spy out their dinner. Unlucky prey might be a small rodent nibbling around the base of the saguaro for its moisture. Predators, such as coachwhip snakes and lizards, carefully make their way up the side of saguaros to eat the eggs and hatchlings in nests.

A home in a saguaro provides better protection than most locations. With arms growing at about ten feet above the ground, few predators can reach a nest built by cactus wrens or hawks in their crooks. Even better are the homes provided by Gila woodpeckers and gilded flickers. These birds dig out holes in saguaros. These holes become not only the homes of the ones who created them, but any bird, insect, mammal, or reptile that might later stake a claim. The inside of the saguaro provides a more temperate living environment. It also collects moisture blown in by storms.

Sometimes a palo verde “nurse” tree diminishes the protection. It provides access to the high nests through its branches. Even as a saguaro dies and rots, it provides shelter to many small animals, including a whole host of reducers and decomposers. The skeletal remains still provide shade on a hot summer day.

Gila woodpeckers

Scientific Name: Melanerpes uropygialis

Description: 8-10 inches long; head and underparts gray-brown, black and white barred back, white wing patches visible during flight, male has small red cap; female and juvenile do not have red caps; tongue long with bristled and sticky tip; chisel-shaped bills; short legs, strong toes, sharp claws; stiff tail feathers; strong head and neck muscles; skull adapted to absorb shock of pecking into trees; nesting of 3-4 eggs, 2-3 times each year depending on food availability

Habitat: desert washes and low desert scrub with saguaro and mesquite trees for nesting; southeastern California, southern Arizona, southwestern New Mexico and into Mexico

Diet: cactus fruit, mistletoe berries, nuts, insects, eggs of smaller birds

Other Info: Gila woodpeckers create nesting holes in saguaros – usually a new one each year. They begin creating the new hole at the end of the old nesting season. The holes tend to be in the older, lower sections of stems. The woodpecker digs out a hole, chunk by chunk of saguaro pulp. This hole lies between the outer skin and the woody rib structure. Even as the woodpecker works to excavate the hole, the saguaro secretes a substance designed to seal off the raw tissue from moisture loss. It also prevents infection. Over several months, the substance or callus hardens and is ready for the new woodpecker nest. Old woodpecker nests then become open to other animals looking for homes. Researchers do not think these holes damage the saguaro, unless too many holes weaken the stem. The hardened callus hole remains after the saguaro dies. Its shape inspires the name saguaro “boot.”

Gilded flickers

Scientific Name: Colaptes chrysoides

Description: 12-14 inches long; brown with black barring on backs; white rumps visible during flying; golden underside of wings and tail, black crescent shape on chest, male has red mustache; tongue long with bristled and sticky tip; chisel-shaped bills; short legs, strong toes, sharp claws, stiff tail feathers, strong head and neck muscles; skull adapted to absorb shock of pecking into trees; nesting 1-3 times per year with 6-8 eggs each time

Habitat: saguaros and woods along desert washes; southeastern California, central Arizona south into Mexico

Diet: ants and other insects, cactus fruit, seeds

Other Info: Two factors influence where flickers make their holes in saguaros. Its size dictates a larger hole. Excavation has to go beyond the wood ribs and into the center of the stem. Secondly, its beak is not a well suited for making holes. The flicker needs to locate the nest higher where the saguaro's ribs are not as close together and not as strong. This is typically in the top ten feet of the saguaro stem. The much larger nest accommodates other large birds after a flicker abandons it. The drawback is that the larger hole tends to damage the saguaro by interrupting the flow of nutrients and moisture in the core of the cactus. Sometimes the saguaro adapts to the damage; sometimes the saguaro dies.

Nurse Plants

Of the millions of seeds produced in a saguaro's lifetime, few germinate. Even fewer live to old age. The secret lies in where birds and other fruit-eating animals deposit seeds. Protected rock crevices provide good germination spots by radiating heat from the rocks. They also collect and conserve moisture. As with most cacti though, the best location involves "nurse" plants. The closer the seed is to the main stem of the plant, the better its chance of survival. This placement is usually courtesy of birds sitting among the branches. Creosote bushes and palo verde trees are favorite "nurse" plants, but saguaros grow under other trees and bushes, too.

The "nurse" plant shelters the young saguaros from the extremes of heat and cold. It also protects from trampling animals and hides the succulent saguaros from moisture seeking rodents. Early years of saguaro life are not usually visible. Then, one day, it peaks above its "nurse" plant and begins life as a mature saguaro. Many times saguaros outlive their nurse.

Damage and destruction of possible "nurse" plants ultimately affects saguaros. Wildfires burn the sheltering plants. Young saguaros die with the loss of protection. Seeds do not have the cover to germinate. Few new saguaros grow in burned out areas until needed habitat returns. Both wild and domestic animals eat away at shielding foliage. The young saguaros die through exposure to heat, cold and animals. Though it sometimes seems that saguaros are dying out, look for new generations hidden beneath their nurses.


For millions of years, the Sonoran Desert grew, shrank and changed as glaciers encroached and retreated. About 9,000 years ago, climate patterns over the North America stabilized. The Sonoran Desert spread into Arizona again, bringing its characteristic saguaros. The range of saguaros continues evolving, expanding, and retreating in relation to the heat and cold of the desert seasons.

They have adapted to the climatic pattern of two rainy seasons. The amount of rainfall is one of the factors in the number of saguaros and their range within the Sonoran Desert. It also influences a saguaro's growth rate, the age at first blooming, the age at first arm development, a saguaro's overall size and the number of blossoms each year.

Months of summer rain follow the month of fruit ripening. The first summer storms germinate deposited seeds. Seedlings only grow with available moisture. They do not yet have enough internal moisture to sustain growth. Summer rains provide more moisture for growth, but they can also wash away the seedlings and very young saguaros. A number of consecutive years with milder and wetter-than-average weather establishes a greater number of seedlings and creates cohorts or groups of saguaros of about the same age.

Winter rains arrive with colder weather. There is a greater risk of freeze damage. The severity of damage to saguaros depends on when the freeze occurs and how long it lasts. Whether a freeze has damaged saguaros may not be known for another decade. Years of plentiful winter rains produce a greater number of blossoms. During dry years, saguaros rely on internal moisture to produce a much smaller number of flowers and fruit. Saguaros continue growing in the winter, but at a slower rate, matching the much gentler rains.

Winter Rains

Summer Rains


Stop #9 – Plant Fibers

Through the seasons, the Sonoran Desert provided for the household and personal needs of its inhabitants. Imagine living the Salado life – no stores full of wares. They collected and harvested everything they needed from the environment around them and from their fields. This was especially true of the fibers required for everything from string to clothing and beyond. They used some animal hair, but the majority of products required various plant fibers. Some of the wild plants, such as agave, were also cultivated. Whether as a food source with extra fiber as an added benefit or whether for the fiber source with food as the benefit is difficult to know.

Processing the materials took time. They coped with each plant's different fiber structure. This determined the preparation and uses of each particular plant. Some plants only needed spines removed, leaves slit to uniform widths, and extra material removed in places for uniform thickness. Some fibers required pounding to break up the outer skin before scraping away skin and pulp. Other plant fibers separated from skin and pulp easier after roasting. All this required a variety of tools including teeth, fingernails, and stone knives.

Once the fibers were prepared, production began. Fibers were twisted or spun for string, cordage, rope and yarn. Workers plaited, coiled and sewed to make baskets. They interlaced strips of fiber leaves to create sleeping mats. Fiber leaves or cordage formed woven sandals. Other textiles, including clothing and blankets, were loom woven. Focus then turned from the practical of supplying basic needs to the expression of creativity. Colors and production techniques provided ways to embellish their products – sometimes simple, sometimes complex.

Some Fiber Plants


Other Common Names: Upland cotton, short-staple cotton
Scientific Name: Gossypium hirsutum var. punctatum
Many prehistoric people of the Americas raised and used cotton. Archeologists believe cotton originated in Peru. It moved north through trade. Species and varieties better adapted for specific environments developed. To grow in central and southern Arizona, cotton needed irrigation. It had to be adapted to arid conditions and unpredictable growing seasons. To survive frost damage, it also had to mature quickly. It grew better than other cultivated plants in the Salt River areas of both the Phoenix and the Tonto Basin. Cotton tolerated the higher salt content of the water and soil. These areas may have had a monopoly on cotton production. Northern pueblos exchanged their pottery for raw cotton and maybe finished products. Earliest seeds in Tonto Basin date to about A.D. 240-390. Evidence of Mogollon/Western Pueblo and Anasazi people growing cotton does not appear until about A.D. 1100.

Below the cliff dwellings, cotton was a significant part of the agricultural activity in the Salt River arm of Tonto Basin. They planted as the mesquite trees leafed out -- a conservative indicator of the passing frost danger. The men made holes with a wooden stick in hills and rows spaced about two feet apart. They buried three to five seeds in each hill. At times, they may have planted two crops in a year. Irrigation canals provided water for cotton plants. The women harvested cotton after gathering in all other crops. They picked the bolls or pods and placed them in areas like rooftops for drying. If late in the season or in danger of frost, they cut or broke off the stalks at ground level before the bolls matured. The bolls could then finish ripening in protected areas. For greater production, they probably used a community labor force.

Next, they prepared the cotton. First, they removed the boll from the raw fibers. Then they separated the seeds and dirt from the fibers, a process now called, “ginning.” They probably used one of two methods. They removed the seeds by hand and threw the fibers on a pile of clean sand to be beaten. The sand cleaned and whitened. The beating fluffed the fibers. In the other method, they placed the raw cotton between two blankets and beat it with a switch. They scraped off the fibers clinging to the blankets. They saved the seeds from both methods for food and future plantings. The fibers were then ready for spinning, dyeing and weaving. Preparing and spinning the cotton may have been women’s work; weaving men’s work. Evidence suggests Salado raised cotton for trade. The people of the cliff dwellings may have specialized in finished textile products as their trade commodity.

The most current theories and knowledge of prehistoric cotton provided information for the prior paragraphs. The Salado people left no written record to tell of their lives. Archeologists combined historical observations and archeological records to develop their ideas. For example, from tools found with burials and early observations of the Hopi and Pima, ideas about the roles of men and women developed. As they learn more, cotton is emerging as an important part of the Salado civilization. Many agree that they do not know enough, especially about its production and trade. As they investigate more, will they develop new theories or reinforce old ones? We may never know the complete story of the Salado.

Sotol (SOH-tole)

Other Common Names: desert spoon
Scientific Name: Dasylirion wheeleri
Description: plant height to 3 feet though some older ones may grow trunks to 6 feet tall, flower stalk height up to 15 feet; green leaves growing out of round basal cluster to 3 feet long and 1 inch wide, sharp teeth on leaf margins facing toward leaf tip; blooms May – August every several years; thousands of tiny, greenish-white flowers with 6 petal-like segments, in long narrow cluster along top part of flower stalk; male and female flowers on different plants
Habitat: growing at 3,000 - 6,000 feet in elevation; rocky slopes in desert grasslands and oak woodlands; primarily a grassland plant with a range extending into the desert
Other Information: Flies, bees, wasps and butterflies are attracted to the flowers for pollination. Besides the fiber uses, sotol provided building material and food. The split flower stalks were used as part of the roofing structure and sometimes the lintel above the doorways. Roasted plant hearts and young flower stalks probably provided food. One piece of sotol mat found during excavation still had the teeth on the edges of the leaves. Who slept on that mat?


Other Common Names: nolina, basketgrass, sawgrass
Scientific Name: Nolina microcarpa

Description: plant height to 3 feet; flower stalk to 8 feet; tough, green, grass-like leaves grow from a basal rosette to 4 feet long and 1/2 inch wide, no teeth on leaf margins, but sharp edges, loose fibers on leaf margins at tips; flowers May – June depending on latitude and elevation; greenish-white to creamy white flowers in dense plume-like clusters along top part of flower stalks; fruits of seeds in a papery sheath in early summer

Habitat: growing at 3,000 - 6,500 feet in elevation; rocky slopes and exposed areas on mountainsides

Other Information: Deer eat the flower heads and stalks. During drought, they will also browse the leaves. Mule deer eat the foliage even in wet years. Humans roasted or boiled the flower stalks and hearts for eating or ate them raw. The fibrous root system helps stabilize hillsides. Thinning the clumps or harvesting the leaves for use increases the production of new foliage. During shortages of World War II, it was a substitute for broom straw in the production of corn brooms.

Plant Types and their Uses

Sotol (Dasylirion wheeleri)

Agave (Agave chrysantha)

Banana yucca (Yucca baccata)

Soaptree yucca (Yucca elata)

Beargrass (Nolina microcarpa)

Cotton (Gossypium hirsutum var. punctatum)

Devil's Claw (Proboscidea sp.)

Archeologists found the long claw of a devil's claw during excavation of the cliff dwellings. In traditional basketry, the black of devil’s claw adds designs and the strong fibers add durability. They did not find any baskets that used the fiber.

River reed (Phragmites)

Salado Textiles

The fabric tradition established by Salado groups is still apparent in fabrics of the pueblos of Northern Arizona. The continuity of this fabric tradition is clear evidence of the importance of cotton to groups in both areas, of the exchange of technology of production and manufacture, and of the timing and source of this exchange. Textiles provide undeniable evidence that Salado groups exchanged knowledge of weaving with their Plateau neighbors. This exchange was preceded by contact between the two groups. I argue that this contact was initiated in the late 1000s, was amplified in the late 1200s, and bore fruit in the subsequent generations of textiles woven by Pueblo groups on the Colorado Plateau.

Pueblo textile designs from about 1250-1450 took on style and structure similar to that of their neighbors to the south, the Salado and Hohokam. This unity in textile designs could be related to the Spread of “Salado Cultures”

Textiles worldwide are important conveyers of information about the wearer, such as wealth and status.


Stop #10 – Stewardship: Use, Protection and Preservation

Coming in Spring 2005


Stop #11 – Desert Wildfires

Talk about wildfires quickly divides into sides -- burn and no burn. Sometimes the “discussions” are as heated as fires themselves. Wildfire in the west is an issue as complex as the many environments which burn. For some of these environments, fire is necessary to maintain health and support new life. For the Sonoran Desert, fire is a destructive force with limited benefits.

Fire is not a natural part of desert ecology. In the Sonoran Desert, evidence points to a history of rare and sparsely located fires, usually revolving around cycles of climatic change. Native grasses and annuals are small and grow farther apart to compete for moisture. After producing seeds, many native plants die back to their root or bulb and leave little plant matter to carry fires, especially large, hot-burning fires. Plants whose new growth sprouts from root systems and bulbs are more adapted to surviving a low intensity fire than others desert plants. The smaller saguaros and cacti are the greatest losers to any fire. On the other hand, saguaros and barrels with larger diameters have some of the lowest death rates. Among animals, wildfire does the greatest harm to populations of the long-living desert tortoise. Over time, frequent fires may forever alter the structure and diversity of Sonoran Desert plant and animal communities.

Why then is fire in the desert becoming more frequent and an increasing problem? Cattle began and limited fire problems. Overgrazing decreased the fuels available and limited fires. Along with overgrazing, came the need to replenish grasses. Re-seeding introduced non-native grass species. These non-native grasses flourished in wet years, limiting growth of low fuel native plants. They also built up fuel. Unlike many native plants, they filled open areas and dry stalks remained in the ground for many years after they died. Adapted to surviving fire, these grasses recovered quicker, choking out native grasses and annuals. In the 1960s and 1970s, seed mixtures used in post-fire rehabilitation further spread non-native grasses. Desert wildfire behaviors changed as fire burned quicker and hotter in these grasses. Fire suppression became policy as economic and environmental values of Sonoran Desert land shifted. It was too late. Non-native grasses had invaded far beyond anyone's expectation. Fires began re-occurring with cycles of fuel build-up, wildfire and further expansion of non-native grasses. Add to the mix an increasing number of houses as urbanization sprawled into desert wildlands. Surrounded by desert vegetation, many homes are not fire proofed. Rather than attacking wildfire and limiting its destruction of plants and animals, firefighters are defenders of structures.

With the establishment of Tonto National Forest in 1905, cattle grazing in Tonto Basin became more controlled, but the damage was already done. Several years after its transfer to National Park Service management, the first fencing of monument lands limited grazing access. They initiated plans to restore grasses and prevent further erosion. This may have been the introduction of non-native grasses to monument lands. If not then, either on purpose or by accident, revegetation efforts after the Schulz Fire of 1964 spread non-native grasses onto monument lands. These were part of the seed mixture used by the forest service in the 60s and 70s to stabilize soil after fires. Over the next sixteen years, three more major fires burned in the same area of the monument. Some experts believe the plant community on the Upper Cliff Dwelling hillside permanently changed due the frequent fires. As the number of years without fire increases, only time will tell about the Sonoran Desert’s ability to recover.

Tonto National Monument Fire Management Plan

At this time, Tonto National Monument's fire management plan consists of suppressing all fires on monument lands and conducting no prescribed burns. This policy provides protection for the natural and cultural resources. With only one road in and out of the monument, it also safeguards visitors and employees. This program ensures prescribed burns do not expand into adjoining forest service lands. The plan’s most important aspect is the directive to gather information about Sonoran Desert fire ecology and managing non-native species before any further monument fire policies are developed.

Saguaros and Fire

Wildfire works against a saguaro's adaptations for survival. As with freeze damage, a saguaro may last nine years or more after fire damage, even blooming and providing fruit, before evidence of impending death appears. Growing among rocks lowers the mortality rate for saguaros and many other plants. Sheltered under a palo verde nurse plant for survival to maturity, a saguaro also has an extremely high risk of dying from the higher heat of the fire as it burns beneath the tree. After fire burns off protective spines, animals have much easier access to the moist pulp, increasing death risk. Recovery of saguaro populations must first await the restoration of nurse plants. Experts believe fires occurring in the same location and less than 30 years apart might eliminate saguaros from an area. Even 30 years may not be enough for shade producing plants to re-establish and saguaros to reach the age to produce seeds.

Tonto National Monument Fire History


In addition to periodic cycles with long stretches of drought or wet, normal climate variations drive fire patterns in the southwest. For Salado and other inhabitants of long ago, the dry months of May through early July were a time of preparing fields, harvesting from the desert and waiting for the coming summer rains. These days, firefighters wait for the coming summer rains to signal the passing of the worst part of the wildfire season. Through 57 years of recorded fire history on Tonto National Monument, five major and several minor fires burned on the monument. The five major fires burned during these dry months before summer rains, all caused by lightning.


Over a series of monthly reports to National Park Service headquarters, the superintendent provided a picture of the conditions providing fuel for fire. It was a dry spring after the preceding wet year in which over fourteen inches of rain fell between July 1946 and January 1947. In contrast, barely half an inch fell for five months -- March through June of 1947. Officials lowered the level of Roosevelt Lake by eight inches each day. They shifted water into the narrower and deeper lakes below Roosevelt Dam to decrease evaporation. Concern about potential problems turned to talk of rationing water and power in Phoenix and Salt River Valley during the summer. A few showers provided relief from high temperatures, but not much else. By mid-July, Roosevelt Lake was dry and the Salt River described as, “a mere ditch of water.”

Though it was the first recorded wildfire on monument lands, very little information exists about the fire, not even the actual date. It may have been the one of two fires reported on the afternoon of July 7. The one on the monument itself was contained within three hours. Nobody reported the fire on forest service lands for several days. It took a week to contain. The only other information is a map, indicating about 40.5-burned acres on the southern boundary of the park. It shows adjacent forest service lands also burned. This was the beginning of fires in Cave Canyon, below the Upper Cliff Dwelling.


It was a year of anticipation as work focused on completion and dedication of the new visitor center. It was also a year of severe drought. Officials declared all of Gila County, including Tonto Basin, a disaster area due to the dryness of the county and surrounding area. Fuel built up with over eleven inches of rain falling from July through December of 1963. January through June saw less than two and a half inches of moisture with no rain falling for the last 62 straight days. The last week of June had temperatures as high as 110 degrees. The three fires in Tonto Basin were only a portion of the many fires fought that year. The first two burned over 1270 acres combined. Sadly, someone may have set one of those fires deliberately.

The third and largest fire, the Schultz Fire, began June 27 outside the monument. By June 30, it had burned 3000 acres and was rapidly burning toward the monument. By July 1, it entered the monument. Fire burned on the hillsides above the new visitor center and across the road from the housing complex. They laid hoses from Roosevelt Lake to the buildings. Firefighters cut fire lines up the hillsides and set backfires. Within twenty hours, the fire was contained on the monument, but had burned 540 acres of the 1120 monument acres. By the time the fire was completely controlled, 4,460 acres of forest service land also burned. Even more devastating was the loss of a life when a tanker plane went down during the fire.


Almost seven and a half inches of moisture fell in the six months after the Schultz Fire. The following year 23.99 inches of rain fell. Both of these assisted with the germination and spread of non-native grasses on the hillside below the Upper Cliff Dwelling. Over the next four years, precipitation varied between above or below the monument’s fifteen inches per year average. By July, the general area had not received rain in four months resulting in very dry vegetation. The temperatures were very hot 24 hours a day with high and variable winds. Perfect condition existed for wildfire.

On July 3, 1970, the Cottonwood Fire ignited south of the boundary. Within about six hours, it was 30 times larger. In addition to high winds, burning sotol plants spread fire quickly as they rolled down the hill. Within another three hours, it increased over 600 times its original size. Four other lightning caused fires burning at the same time on the Tonto National Forest stressed available firefighters. Hotshot crews from outside the state arrived to help. An aerial survey on July 6 gave reason to believe the monument was in trouble. Superintendent Schaafsma ordered an all out effort to save the visitor center and housing complex. He reported, “By sundown the heat and smoke was very oppressive and a feeling of impending oblivion was experienced by all concerned.” They bulldozed a fire line on one hillside, using the same line as the Schultz Fire. On the other hillside, a crew from Bitterroot National Forest cut a fire line from the bottom of the canyon to the Upper Cliff Dwelling – 600 feet almost straight up. They set backfires, even as fire was moving in on their location. Through valiant efforts by National Forest Service crews to save the cliff dwellings, visitor center and other buildings, the fire was contained to 200 acres on the monument. In comparison, 6,170 acres of forest service land burned.


Another six years, another major fire burned. In the intervening years three less than acre-sized lightning fires burned. Yearly rainfall totals were about average other than one very wet year and one year a bit drier. Nothing to indicate fire should be of particular concern. By now though, two fires and several wet years helped non-native grasses invade the area.

On May 18, 1976, lightning started the Monument Fire on a ridge near the southern boundary. The vegetation around the Upper Cliff Dwelling burned before fire crews could reach the area. A strong wind from the storm drove the fire toward the visitor center. Fire crews used previous fire lines to conduct their attack. After the storm center passed, winds changed direction. Fire jumped across the canyon. Slurry drops just before dark missed their mark. During the night, fire jumped a line and burned back into the monument near the housing area. Light drizzle during the night helped to cool the fire and it was contained in early morning hours of May 19. This time fire burned 1,080 acres with 250 acres on monument land. The hillside of the Upper Cliff dwelling burned for the third time in twelve years.


Only four years passed since the last major fire burned on monument lands. The first year after the 1976 Monument Fire, rain measured only 10.19 inches. This dry time after the fire benefited native plants adapted to the dryness. This was not to last. In 1978, 36.94 inches of rain fell, the most in monument history. The following year had only slightly above average rainfall. A lightning caused fire of only an acre burned in a remote area in 1979. Fifteen of the monument’s 1980 total 21.25 inches of rain fell in the first six months, with limited amounts in May, June, and July. Non-native grasses benefited from the wet years, building up fuel to support fire.

On the night of July 23, lightning began a fire about a half-mile from the monument’s southern boundary. Mid-morning of July 24, the original fire re-ignited or there was another fire in the same area. The second “Monument Fire,” sometimes called the "Honey Fire," entered the park late afternoon on July 24, along most of the southern boundary. Monument personnel stood by fire hoses to protect the visitor center and housing area. Two slurry drops on and behind the visitor center assisted with protection of the building. By early evening, fire burned hot and fast along the hillsides of Cave Canyon, heading toward the visitor center. Firefighters used previous fire lines to set backfires. Monument personnel put out the last of the hotspots by mid-afternoon on July 27. Just over 1,000 acres burned including about 100 acres of monument land. This was the last major fire on the monument. Two very small lightning fires burned in 1983 and 1984. Neither of these burned in Cave Canyon.


Stop #12 – Cave Canyon Watershed

We all live in watersheds. The definition is the same whether talking about the great Mississippi watershed or smaller Cave Canyon. The area of land in which rain is “shed” from the highest elevation to a certain point or outlet defines each watershed. It is like a tree — its leaves represent the upper elevations and the trunk base is the outlet. Larger watersheds contain branches of many smaller watersheds. Cave Canyon is part of the Colorado River watershed, combining with two other watersheds before reaching the river in southwest Arizona. In many areas, the constant flow of streams and rivers is a reminder of contaminants moving from their source to their outlet in the ocean. For many desert watersheds, seldom is more than potential water flow seen in empty washes, arroyos and streambeds. Some forget how the care and treatment of these dry places and surrounding lands affect downstream areas during future flows.

Park history records few flash floods in Cave Canyon, creating the idea they were rare events. Further study of the watershed by scientists tells a different story. Cave Canyon watershed consists of 670 acres or 271 hectares of steeply sloped land. In most areas, the soil is shallow and covers bedrock. Water cannot soak into the soil and rushes off hillsides, carrying eroded materials. Once reaching washes, water travels through downward sloping channels with continued speed. Average rainfall is greater in the watershed’s higher elevations, adding to these conditions. In addition to protecting natural resources, the park is concerned about visitor safety. As with all desert hiking, park personnel consider upper watershed storm conditions before leading hikes to the Upper Cliff Dwelling through Cave Canyon.

Several factors influence the watershed in Cave Canyon, some controllable, some not. First, climatic factors change the severity of flooding. Size and location of a thunderstorm within the watershed controls the amount of rain released to hillsides. In years with enough moisture, vegetation growing on the hillsides slows run-off and prevents erosion. On the reverse side, in drought years, plants become dormant, shed root systems or even die out. When a storm hits, lack of vegetation means greater erosion and increased runoff. At times, even sediment eroded from the hillsides drastically alters the Cave Canyon wet riparian area. High speed and large amounts of water transport greater amounts of sediment. As water slows down, the sediment drops out before reaching the outlet. In 2003, about 4 inches (10 cm) of sediment deposited in the riparian area and covered the channel of water flow from the spring. For almost a year, water ceased to flow along the surface. In 2004, another flood event scored out a channel for the spring water to follow on the surface. In these cases, nature is beyond man’s control.

Another factor affecting Cave Canyon is the boundaries. Where rain falls and flows defines a watershed, not fences. A greater portion of Cave Canyon watershed is within Tonto National Forest, open to multiple uses. Cattle still graze in Cave Canyon watershed. Cattle grazing may cause loss of vegetation, compacted soil and unstable wash banks. All of these changes result in increased runoff, soil erosion and the possibility of damaged riparian vegetation. As water runs from multiple use lands to protected lands, it also carries seeds of non-native species and anything else that might have a harmful impact. Limiting these land use factors is an important part of protecting sensitive habitat further down the watershed.

At one time, concerns about protecting the riparian habitat in Cave Canyon led to talk of adding Tonto National Forest watershed acreage to the park. Today, focus is on cooperatively managing the shared watershed. As part of the NPS Sonoran Desert Network, Tonto National Monument recently completed a baseline study of plants, animals and water in the riparian area. These inventories serve as a base for future study of Cave Canyon. Two monitoring priorities are water quantity and quality. This includes measuring groundwater depth and depth to wet soil. Two other priorities are soil erosion and watershed conditions. For these, the park will monitor channel changes, water flow, and sedimentary deposits through special equipment. Tonto National Forest will use data collected through their Terrestrial Ecosystem Survey to monitor soil erosion and watershed conditions in their section. Comparison of current data with baseline data will influence land use decisions in Cave Canyon watershed. According to baseline studies, the riparian area changed and adapted to conditions of frequent disturbance and recovery. Monitoring future changes in Cave Canyon watershed and riparian area will help us understand this evolution and limit man’s impact.


Stop #13 – Wildflowers

Tonto National Monument is a wonderful place for viewing the showy spring wildflowers. In a good year, the hillsides are covered with gold poppies. Blooms of purple lupine, red paintbrush, white desert chicory along with many other species are scattered among and above the gold. Though some flowers were of use, Salado looked forward to harvesting the fruit and plant parts. The desert was their grocery store, and each plant a shelf of foods, medicines and other items supplementing their cultivated crops. The Salado also had to compete with the many animal species relying on the same plants for their food. A bountiful flowering season meant a bountiful harvest for both animals and humans.

Spring is not the only time for wildflowers in the desert, just the most abundant. Many cacti bloom at their appointed time during the year. The bright pink blooms of the hedgehog arrive in March and April, while Arizona’s state flower, the white saguaro blossom, opens in May, and June. The agave family of plants, including yuccas, bloom from late spring through the summer months. These and other perennial plants continue to live from year to year with their blooms not as dependent on the timing of the rain.

Plants completing their life cycle in one growing season are called annuals. No matter their blooming season, these plants are very dependent on the right conditions to germinate. This is especially true of the spectacular spring flowers. Some seeds may lie dormant a decade or more, waiting on the weather. Without the right amount of rain in the autumn, the growing process for spring blooming does not even begin. Best wildflower years have unusually wet and early winter rains. The rains also have to be carefully spaced apart. Along with the rains, the right temperature is important. Cold winters may slow the growth of the seedlings. Warm windy weather may dry out the seedlings causing them to bloom prematurely. Other factors affecting growth may include too much vegetation from a wet summer and different soil types. Don’t forget the affect of animals browsing tender shoots or crushing plants in their wanderings. At the end of their cycle, hundreds of seeds are spread across the hills and valleys by wind, water and animals, only to play the waiting game again. Next time wildflowers dress the landscape, know that conditions happened just right to grace us with this amazing display.


Stop #14 – River Valley

Coming in Spring 2005


Stop #15 – Location, location, location

Why, in this place? One question, but thought about in two different ways. There are cliff faces throughout the basin, some with caves and some not. Why did caves form in these specific cliffs and a certain area of the cliffs? There is a more common, but also more difficult question. The river and farmland was several miles away. It was a steep climb, especially in yucca sandals. Why did the Salado build in these caves? Water is an easy answer to both questions, but they also have answers that are more complex. The answers about cave formation provide a more complete picture. The answers about the Salado’s choice of homes usually involve more questions.

The geologic answers are easier to understand. First, the caves formed in rock layers especially prone to spalling or rock pieces breaking off. Joints and fractures may be more numerous in the cave area, breaking the rock layers into smaller pieces. The joints and fractures also create pathways for water to follow, dissolving cement holding rock layers together. Secondly, the right combination of harder rocks and easily spalled rocks is in the cave areas. With harder rocks above and less resistant rocks below the spalled area, a cliff overhang with a slanted hill below occurs. With less resistant rocks above and harder rocks below the spalled area, a steep cliff with a slanted hill above occurs. Only with harder rocks above and below the easily spalled rocks did the caves form. The more resistant rocks limit how far and where the spalling happens. Finally, debris cemented to cliff faces, remnants of Gila Conglomerate, protects the cliff face from erosion. Breaks in the plaster allow erosion to begin. The plaster also creates a dam, forcing water to remain in easily spalled areas. Geologic conditions were just right for caves to form in these cliffs.

The answers to the Salado’s choice of these cliffs are not as easy. First, consider how close resources were to the site. Of major importance was the availability of water through the seepage in the back of the Upper Dwelling and the year round spring in the canyon below. They did not have to travel to the river to obtain water. The cave provided shelter and rocks for building. No signs exist of their working the cave walls to provided space. The size of the cave determined the size of the building. Next, defense and protection comes to mind. However, no marks of attack occur in the walls or rooms. Evidence does suggest they had on-going contact with people living in the lowlands, probably of an economic nature. Some theorize these dwellings specialized in certain products, possibly the production of finished cotton goods. It would be important that these spinners and weavers not live in areas potentially used for farm fields. Would the authorities or religious leaders use these high places to track the rising of the sun and moon? These tasks were important to other agricultural societies. Puebloans to the north and Mayans and Aztec to the south tracked the moon and sun. Salado traded with people to the north and south. Immigrants moved into Tonto Basin from northern pueblos. Were Salado influenced by the northern and southern people? The outer walls, which might have answered this question, are long gone. Theories about their choice of these home locations will continue as long as there are no concrete answers.

Whatever geologic and cultural reasons for this location, their stories became entwined. The dwellings draw attention to the caves which otherwise would be passed over. They do not have the fantastic structures seen by visitors in closed, living caves. The caves in turn, sheltered the dwellings from erosion and provided a place to visit this long ago culture. Walls outside the cave’s drip line are long gone. The caves also protected pieces of Salado life, now studied for answers. The dryness of the caves and dwellings preserved far more evidence than many exposed sites. As they say in the real estate market – location is everything.


Stop #16 – Historic Views of the Upper Cliff Dwelling

Coming in Spring 2005


Stop #17 - Upper Cliff Dwelling Floor Plan

Coming in Spring 2005



Cactus Patch Trail (current location)

Upper Cliff Dwelling

Lower Cliff Dwelling


The Salado (Tonto Web Site)

Natural Resources (Tonto Web Site)


Views Visitor Center

Help Center