Paleontological Resources Near Yellowstone
Gallatin Petrified Forest
Extensive outcrops of petrified forest are exposed within national forest areas just north and northwest of Yellowstone National Park. The
Gallatin National Forest includes approximately 25,980 acres
of land designated as a special management zone
referred to as the Gallatin Petrified Forest, which is
geologically equivalent to similar exposures within Yellowstone.
The U.S. Forest Service has developed an interpretive
trail along cliffs containing petrified wood fragments.
Although collection of petrified wood is prohibited along the trail, up to 20 cubic inches can legally be collected for non-commercial purposes per person per year elsewhere in the Gallatin National Forest. A self-serve permit station is located at the entrance to the Tom Miner Petrified Forest or at one of the U.S. Forest Service district offices.
Yellowstone River Valley
The Middle Miocene Hepburn's Mesa Formation north of Yellowstone National Park preserves the remains of fossil vertebrates. Tony Barnosky (Montana State University) has studied Barstovian mammals from this formation.
The Chalk Cliffs, north of Gardiner near Old East River Road, contain Miocene fossil vertebrate remains including horse, turtle and shark's teeth. Fossil equid limb bones from Chalk Cliffs are in the Yellowstone Park Museum.
The area surrounding Cooke City just outside the northeast park entrance contains extremely rich fossil deposits, primarily Paleozoic sedimentary layers that contain an abundance of invertebrate fossils. From the Devonian Beartooth Butte Formation, which contains Lower Devonian plant and fish fossils representing a estuary along an ancient sea coast, five ostracoderm fish species have been identified.
Early and Middle Eocene fossil vertebrates have been collected in Wapiti Valley just east of the park. Fossils ranging in age from Wasatchian through Bridgerian have been collected by paleontologists from the University of Michigan in the exposed sediments and volcaniclastic rocks exposed in the north and south forks of the Shoshone River.
Other fossil vertebrate localities east of the Absaroka Mountains which have been studied by Jeff Eaton have yielded primarily Eocene fauna. Paleontological surveys along the eastern boundary of Yellowstone, especially the Hoodoo Peak and Bootjack Gap areas, may yield similar age deposits and fossils.
Bridger-Teton National Forest
Exposures of the Cretaceous Harebell Formation can be found just south of the park. Dinosaur footprints were recently discovered by Kirk Johnson (Denver Museum of Natural History) in the Bridger-Teton Wilderness Area.
Eocene, Oligocene and Miocene vertebrate fossils are known from the Emerald Lake area, three miles south of the park. The White River and Colter Formations contain Chadronian through Arikareean fossil mammals (Love et al. 1976).
The Hominy Peak Formation, which is exposed along the southern boundary of Yellowstone National Park, contains Eocene flora and vertebrate fossils corresponding to Bridgerian A-B fauna (Love et al. 1978).
Vertebrate fossils ranging from Uintan through Whitneyan are known from the Gravelly Range, west of the park.
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