The White River Formation is a geologic formation of the Paleogene Period, in the northern Great Plains and central Rocky Mountains, within the United States.
| White River Formation | |
|---|---|
| Stratigraphic range: Late Eocene-Early Oligocene (Chadronian-Whitneyan) ~37.2–30.8 Ma
| |
| |
| Type | Formation |
| Sub-units | Brule Formation, Chadron Formation[1] |
| Overlies | Pierre Shale |
| Thickness | 230–300 m (750–980 ft)[2] |
| Lithology | |
| Primary | Tuffaceous claystone, conglomerate[3] |
| Location | |
| Coordinates | 43°12′N 107°06′W / 43.2°N 107.1°W / 43.2; -107.1 |
| Approximate paleocoordinates | 44°48′N 98°24′W / 44.8°N 98.4°W / 44.8; -98.4 |
| Region | Colorado, Nebraska, South Dakota, Wyoming |
| Country |  United States |
| Extent | northern Great Plains & central Rocky Mountains |
| Type section | |
| Named for | White River (Missouri River tributary) |
  White River Formation (the United States)  White River Formation (Wyoming) Show map of Wyoming | |
It has been found in northeastern Colorado, Dawes County in western Nebraska, Badlands of western South Dakota, and Douglas area of southeastern Wyoming.[1]
The geologic formation preserves fossils dating back to the Eocene and Oligocene Epochs of the Paleogene Period, during the Cenozoic Era.[4] It contains the most complete Late Eocene−Priabonian and Early Oligocene−Rupelian vertebrate record in North America.[1][5]