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National Recreation Area


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park geology subheading
Photo of bridge at Chickasaw National Recreation Area
Chickasaw National Reareation Area, Oklahoma
Although only a limited number of geologic studies had been conducted within the confines of CNRA at the time of this report, the Arbuckle Mountains have been studied extensively (e.g., Decker and Merritt, 1931; Ham, 1955, 1969, 1973; Johnson et al., 1984). Regional scale information obtained from studies of the Arbuckle Mountains provides insight concerning the general geology of CNRA.

The Arbuckle Mountains are a high range of hills located between Davis and Ardmore, Oklahoma. The structure of the Arbuckles consists of three northwest-southeast trending anticlines known as the Hunton arch, and the Tishomingo and Arbuckle anticlines (U.S. Department of Interior, 1982).

Tapp (1997) provides the following geologic and tectonic chronology of events within the Arbuckles. During the Cambrian Period, (570 to 500 MYA), a large-scale faulting event (a triple junction aulacogen) formed a rift valley known as the Southern Oklahoma Aulacogen.

During the Ordovician Period, (500 to 430 MYA), the rift ceased spreading and a broad, shallow sea began to encroach over the entire region. For the next 200 million years, marine sediments accumulated on the sea floor. The calcium-rich bodies of dead sea organisms also formed thick limestone layers; in some areas, limestone and shale deposits reach thicknesses of up to two miles.

Another major geologic episode in the region occurred during the Permian Era (280 MYA to 225 MYA). During this episode, the region's crust was forced upward, presumably by the Arbuckle Orogeny (uplift event). The force of this upheaval was so great that many of the sandstone, shale, and limestone layers were broken and folded, creating large anticlines. Along with the folding process, this upward thrust formed the Arbuckle Mountains.

The Arbuckle Mountains have been severely denuded as a result of millions of years of erosion. The mountains now appear as a moderately dissected, low plateau (Harp et al., 1976). Regional geologic studies also show CNRA's geology to be dominated by a syncline having a west-northwest plunging graben (Hanson and Cates, 1992).

In general, the geological complexity of the area is reflected by the high frequency of faults and folds. Some of the fault variations seen in the area include dip-slip, strike-slip, and overthrust faults. There are two main faults within this region: the North Sulphur and the South Sulphur Faults. The dominant fault found near CNRA, the North Sulphur Fault, can be traced from eight miles southeast to one mile east of CNRA (Hanson and Cates, 1994). The South Sulphur Fault can be traced two and a half miles southeast of CNRA to where it parallels to the North Sulphur Fault. Despite the availability of information about them, the extent to which these and other faults influence groundwater flow in CNRA is unknown.

Although the area surrounding CNRA is geologically complex, it is situated in a region that is considered to have low seismic activity and has historically been free of high magnitude earthquakes. A plot of regional earthquake epicenters shows that no historical earthquakes have occurred within a 20-mile radius of CNRA. Earthquakes detected outside this 20-mile radius have had magnitudes less than 4.0 on the Richter scale. However, a level of uncertainty about seismic activity in the area remains, given the fact that CNRA is located only 50 miles to the west of the Nemaha uplift. This ridge is composed of a deeply buried granite traversing north-south from Nebraska to Oklahoma (U.S. Department of Interior, 1982). In this uplift is a zone of deep-seated faults, known as the Humboldt fault zone, which has been determined to be seismically active by the Kansas Geological Survey (U.S. Department of Interior, 1982).

There are three primary rock units in the subsurface of CNRA. The predominant surface rock is the Vanoss Formation, consisting of a limestone conglomerate (Cates, 1989). The Simpson Group, comprised of limestone, sandstone, and shale, lies beneath the Vanoss. The deepest and oldest major unit is the Arbuckle Group, which consists of dolomite, limestone, and sandstone.


CNRA is located in south-central Oklahoma midway between Dallas, Texas and Oklahoma City, Oklahoma. Occupying approximately 9,888 acres, CNRA is situated at the juncture of the southern Osage Plains and the ancient, worn down remnants of the Arbuckle Mountains (Barker and Jameson, 1975).

At the continental physiographic scale, CNRA is located at the southern terminus of the interior plains, a region that extends from central Canada to the south-central United States, and is bounded on the west by the Rocky Mountain System and the Appalachian Highlands to the east. On a regional scale, CNRA is located in the physiographic province known as the Arbuckle Uplift (see Figure 4). As noted by Tapp (1997), this province contains some of the thickest accumulations of Paleozoic rocks in the central United States with ages ranging from 570 to 245 million years ago (MYA).

Two major geological events influenced the geology of this region. The first major event was large-scale faulting that formed enormous rift valleys much like those in eastern Africa. The rifting arm extended from the Ouachita Mountains on a southeast-northwest line to the western area known as the Anadarko Basin. Following this event, thick accumulations of sediments formed within the shallow rift valley and currently comprise a large part of the stratigraphic column of the Arbuckle Uplift region. Even thicker accumulations of sediments can be found to the northwest in the Anadarko Basin region.

A deformational process was the second major event that transformed this region. This is displayed within the Arbuckle Uplift region and can be seen in deformed rocks, numerous faults, and other tectonic features such as anticlines and synclines (Tapp, 1997). The greatest deformation in the region, however, occurred in the Ouachita Uplift province, which is located east of the Arbuckle Uplift. Rifting and deformational events also affected other areas within the region, including the Arbuckle- Wichita Trend. A more detailed description of the regional geologic history can be found in the geological section of this plan.

Landforms within CNRA vary from steep ridges dominated by weathering resistant outcrops of conglomerate rock, to valley floors that are drained by several streams. Topography generally slopes to the southwest, with the high point located at the Bromide Hill Overlook (Sallee and Schoneweis, 1997). Surface elevations in CNRA vary from almost 1200 feet above mean sea level (msl) southeast of Veterans Lake to 800 feet above msl at the Lake of the Arbuckles. The gentlest slopes within CNRA occur in northern portions of the area along streambeds. One such location is found along Travertine Creek, where the NPS has established numerous recreational sites.

CNRA's topographic variation is influenced by the diversity of rock types and their respective susceptibility to erosion. The high points of CNRA, located around Veterans Lake, are covered with erosion resistant Vanoss Conglomerate while some of the lower lying areas, where creeks cut through, are covered with less resistant carbonate formations. Some formations contain alternating layers of sandstones, shales, and limestones. The erosionresistant sandstone rocks form topographic highs while the less resistant carbonates and clays form topographic lows, giving portions of the area a characteristic hilly topography.

Rock Creek Drainage Basin (see Figure 5) makes up the main drainage area of CNRA. This basin contains several streams including Travertine, Rock, Guy Sandy, and Buckhorn Creeks, all of which feed into Lake of the Arbuckles. Meanwhile, Wilson Creek is the main source of water for Veterans Lake. Stream flow in the area is supplied year-round by the area's numerous natural springs.


Since the Arbuckle Orogeny, which occurred between 225 and 280 MYA, the landscape of CNRA has been constantly changing through gradational processes. Gradational processes mechanically shape or grade the geological structures into the landforms seen today (Ritter, 1978). The overall process of change on the earth's surface is known as geomorphism. There are five principal geomorphic agents used to shape the land: surface water, groundwater, waves and currents, glaciers, and wind (Ritter, 1978). Of these five agents, water plays the most prominent role in shaping the landscape of CNRA (Barker and Jameson, 1975).

Formation of Rock Creek and Bromide Hill Much of CNRA's landscape has evolved over the last few thousand years during the Quaternary geologic period. Rock Creek is perhaps the dominant geomorphic feature within CNRA. This Creek formed in an area that was higher than the surrounding region because of its location near the Arbuckle Uplift. Persistent runoff north and east of CNRA, along with base flow from several springs, led to the formation of Rock Creek, which cuts across the very resistant Vanoss Formation. Rock Creek has carved an extensive v-shaped valley through the resistant conglomerate that extends several miles and reaches depths of over 150 feet (Barker and Jameson, 1975). Lateral differential erosion has widened the valley in a southward direction. This process often happens when two or more materials of differing resistance are eroded by the movement of water. The resistant Vanoss conglomerate, in this case, erodes at a slower rate than the shale and sandstone layers of the underlying Simpson Group.

Bromide Hill, which continues to be shaped by Rock Creek, is the most recognizable topographic feature within CNRA. This undercutting action of the creek weakens rock overhangs which then fall into the creek. Remnants of such rock falls can be found 100 yards east of the Rock Creek campground (Barker and Jameson, 1975). Some parts of Bromide Hill are also affected by mass wasting, which results when small portions of rock and soil roll down the face of the hill into Rock Creek. Although both undercutting and mass wasting occur at a slow rate, the combined effect of these two actions will eventually lead to the leveling of Bromide Hill.


Chemical and physical characteristics are important controls on the type of soil that forms in a given area. The principal controls on soil formation are: (1) parent material; (2) topography on which the soil forms; (3) amount and type of vegetation; (4) climatic conditions; and (5) the length of time over which changes in the soil can take place (Brady, 1990). Physiographic conditions within CNRA have led to the formation of a number of distinct soil types (Table 1), as identified by the U.S. Department of Agriculture (1984). Barker and Jameson (1975) have suggested a simple classification that recognizes two basic physiographic environments within CNRA. They have also categorized resident soils into two generalized types, lowland soils and upland soils. In many cases the valley walls serve as a transition zone between the lowland and upland soil areas.

Lowland soils within CNRA are found primarily along watercourses and are principally composed of transported alluvial material (Barker and Jameson, 1975). The parent material for these soils is primarily shale. As a result, these soils are mostly clay loams with small amounts of flood-deposited sand in their upper few inches. The lowland varieties are the deepest (7-10 feet) and darkest (heavy reddishbrown) soils located within CNRA (Barker and Jameson, 1975). The clay and silt alluvium, forming lowland soils are nutrient rich and retain water well, making them very fertile. Lowland regions of CNRA are highly diversified in terms of fauna and micro-flora. The large amounts of decaying vegetation which falls on the forest floor raises soil acidity and gives the soil a chemical makeup that is characteristic of a forest environment.

Upland areas within CNRA are covered by residual soils formed by in situ breakdown of the parent rock material (Barker and Jameson, 1975). The dominant surface formation within CNRA is the Vanoss conglomerate, which forms thin (2-8 inches) soils that are generally graybrown in color. The large amounts of cobble and gravel found within the upland soils places them in the rough-stony category (U.S. Department of Agriculture, 1984). The Vanoss conglomerate is very resistant to weathering, and tends to form steep slopes. As a result, soilforming processes are slow relative to erosion and water retention is generally poor. These factors combine to limit soil development and vegetative growth. Soil forming characteristics of the Vanoss conglomerate tend to create base rich or alkali soils. This is consistent with the dominant semi-arid grassland environment found within the area.

Source Water Resources Division https://www.nature.nps.gov/water/completedwrmp.htm


Barker, B.M., and C. Jameson. 1975. Platt National Park : Environment and Ecology. 1 st ed. Norman , Oklahoma . University of Oklahoma Press.

Cates, S.W. 1989. Fault Distribution in the Sulphur , Oklahoma Area Based on Gravity, Magnetic, and Structural Data. Department of Geology MS Thesis. Norman , Oklahoma . University of Oklahoma ,

Decker, C.E., and C.A. Merritt 1931. The Stratigraphy and Physical Characteristics of the Simpson Group; (Includes Geologic Map of the Arbuckle Mountains , Oklahoma by CE. Decker, C.L. Cooper and Rex Mcgehee). Oklahoma Geological Survey Bulletin 55.

Ham, W.E. 1955. Geology of the Arbuckle Mountain Region. Oklahoma Geological Survey Guidebook 3.

Hanson, R.L., and S. W. Cates. 1992. Appraisal of the Hydrology of the Chickasaw National Recreation Area. Murray County , Oklahoma . USGS. Water­Resources Investigations Report 92.

Hanson, R.L., and S. W. Cates. 1994. Hydrogeology of Chickasaw National Recreation Area, Murray County , Oklahoma . Oklahoma City , Oklahoma . USGS. Water-Resources Investigations Report 94-4102.

Harp, J., J. Laguros, S. McClin, and L. West. 1984. A Comprehensive Flood Study of the Travertine and Rock Creek Areas within the Chickasaw National Recreational Area. Sulphur , Oklahoma . Norman , Oklahoma . The Bureau of Water Resources Research, Oklahoma Research Administration and The University of Oklahoma .

Johnson, K. S., M.R. Burchfield, and W.E. Harrison. 1984. Guidebook for Arbuckle Field Trip, Southern Oklahoma . Oklahoma Geological Survey Special Publication 84-1.

Ritter, D.F. 1978. Process Geomorphology. Dubuque , Iowa . Wm. C. Brown Publishers.

Sallee, K., and P.J. Schoneweis. 1997. A Cultural Landscape Inventory of the Platt District. Sulphur , Oklahoma . U.S. National Park Service.

Tapp, B. 1997. "Tectonic Provinces of Oklahoma ."

U.S. Department of Agriculture. 1984. "Soil Survey of Murray County , Oklahoma ." Washington , DC .

U.S. Department of Interior. 1982. "Seed Report on Veterans Dam." Washington , DC .


Mineral or Fresh, the Attraction Was Always Water
Chickasaw National Recreation Area draws together old and new and honors the Chickasaw Nation's contributions toward preserving startling natural features in this nearly level landscape. The recreation area was established by Congress in 1976 by combining Platt National Park and Arbuckle Recreation Area. Arbuckle was created with construction of the Lake of the Arbuckles in the 1960s.

The attraction was always water, whether mineral or fresh. Many who thronged Sulphur in bygone days sought health or healing from the sulphur and bromide spring waters available here. Medical opinion of that day found mineralized waters curative and restorative. Medical opinion has shifted, but the springs still freely offer their distinctive waters to the curious, both skeptic and believer alike. Rock formations and mineral deposits along the streams add to the interest of the Travertine area.

Early visitors from surrounding prairie areas, like earlier Indians, were attracted by the clear, cool streams and the surrounding shady woods. Early Indians found good hunting here, a result of the unique combination of woodlands, prairies, and year round fresh water. New visitors to Chickasaw continue older traditions of recreation. Walking up from the stream along the trail east of the nature center you pass from an eastern woodland into prairie and back again in just a few steps. Biologists call this the "edge effect", where the life communities meet. The many choices of food and shelter available where woodland meets grassland support an abundance of wildlife. It explains why early Indians found good hunting and today's visitor may have a chance to catch a glimpse of wildlife.

Surprisingly, you can see the Southwest's roadrunner in the same woods as the East's cardinal. Walking from the stream up to the ridgetop you pass through sycamore, pecan, hickory, and eastern red cedar of the eastern woodlands. On the ridge you find grass and prickly pear, representing western prairie. Keep an eye out for the fox squirrel, armadillo, whitetail deer, beaver, gray fox, skunk, bobcat, green snake, birds, and wild turkey. Watch for poison ivy too. If you are not familiar with this irritating plant, ask at the nature center for the description.

Geologically speaking there is more to this ridgetop than may meet the eye. Hills are not uncommon in this immediate region, but this hill is a northeastern foothill of the Arbuckle uplift of mountains. The uplift was dramatic-nearly vertical folds of rock are exposed in the highway cuts of Interstate 35 just south of Davis, Oklahoma. The mountains are so old that they are now worn down to their present levels, literally to their roots. It is believed they were once as massive as today's Rocky Mountains. The uplift trends east and west, too, in contrast to the continent's predominantly north-south mountain trends. Rock in the Arbuckle Mountains may be the oldest you will ever see. The uplift occurred some 300 million years ago.

It is from these foothills that Buffalo and Antelope Springs issue to supply freshwater to Travertine and Rock Creeks. A short, pleasant woodland walk east of the nature center brings you to these springs. There is something exciting about reaching the "headwaters" of a stream, such as Travertine, and following it to its first major con-fluence, at Rock Creek near Black Sulphur Spring, and then maybe swimming or boating in a lake it helps fill, Lake of the Arbuckles, all in one day. This you can do here. Waters from Buffalo and Antelope Springs eventually end up in the Washita River on their way to the oceans.

Bromide Hill is a popular place at Chickasaw. Winding your way along the well-developed foot trail on this northern face you traverse sedimentary rock deposits which are 270 million years old. (Don't worry, the walk takes you only a few minutes.) Some layers look like the usual sandstones and shales. Other layers suggest that a concrete truck dumped its payload there. But looking around at the mass of this concrete-like, naturally cemented gravel, sand, and cobble quickly changes your mind. No truck could do it. This conglomerate, as it is called, caps the whole of Bromide Hill. But the view at the top caps your climb. It's a rare treat in this nearly level region and makes those switchbacks worthwhile. Many an Indian and early settler must have detoured by here for one good look around.

Bicycles are allowed except on trails east of the nature center, but they are not recommended on Bromide Hill trails. Gone are the mules, and the passenger train too, so your best bet is to come here by car. Chickasaw lies near Sulphur, Oklahoma on routes U.S. 177 and State 7, accessible from Oklahoma City and Dallas-Fort Worth via Interstate 35.

Public transportation facilities do not serve the recreation area conveniently. Bus service is available to and from Davis, Oklahoma, 16 kilometers (10 miles) away. Amtrak trains stop at Ardmore and Pauls Valley, Oklahoma, 56 kilometers (35 miles) and 47 kilometers (29 miles) away, respectively. The nearest commercial airline service is to Oklahoma City.

Summers are hot and humid. Temperatures above 37°C (100°F) occur and humidity frequently exceeds 50 percent. Winters are generally mild and rarely subject to prolonged freezing temperatures. Severe thunderstorms are common from May through June.

park maps subheading

The General park map handed out at the visitor center is available on the park's map webpage.

For information about topographic maps, geologic maps, and geologic data sets, please see the geologic maps page.

photo album subheading

A geology photo album has not been prepared for this park.

For information on other photo collections featuring National Park geology, please see the Image Sources page.

books, videos, cds subheading

Currently, we do not have a listing for a park-specific geoscience book. The park's geology may be described in regional or state geology texts.

Please visit the Geology Books and Media webpage for additional sources such as text books, theme books, CD ROMs, and technical reports.

Parks and Plates: The Geology of Our National Parks, Monuments & Seashores.
Lillie, Robert J., 2005.
W.W. Norton and Company.
ISBN 0-393-92407-6
9" x 10.75", paperback, 550 pages, full color throughout

The spectacular geology in our national parks provides the answers to many questions about the Earth. The answers can be appreciated through plate tectonics, an exciting way to understand the ongoing natural processes that sculpt our landscape. Parks and Plates is a visual and scientific voyage of discovery!

Ordering from your National Park Cooperative Associations' bookstores helps to support programs in the parks. Please visit the bookstore locator for park books and much more.

geologic research subheading


For information about permits that are required for conducting geologic research activities in National Parks, see the Permits Information page.

The NPS maintains a searchable data base of research needs that have been identified by parks.

A bibliography of geologic references is being prepared for each park through the Geologic Resources Evaluation Program (GRE). Please see the GRE website for more information and contacts.

selected links subheading

NPS Geology and Soils Partners

NRCS logoAssociation of American State Geologists
NRCS logoGeological Society of America
NRCS logoNatural Resource Conservation Service - Soils
USGS logo U.S. Geological Survey

teacher feature subheading

Currently, we do not have a listing for any park-specific geology education programs or activities.

For resources and information on teaching geology using National Park examples, see the Students & Teachers pages.
updated on 01/04/2005  I   http://nature.nps.gov/geology/parks/chic/index.cfm   I  Email: Webmaster
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