Search SEDIS
| Data sets | Publications | Expeditions | Thesaurus |
White River Group  | |
|---|---|
| BT | Chronostratigraphic Units |
| .Phanerozoic | |
| ..Cenozoic | |
| ...Paleogene | |
| ....White River Group | |
| RT | Oligocene |
| Wyoming | |
| Montana | |
| Colorado | |
| Nebraska | |
| North Dakota | |
| Arikaree Group | |
| South Dakota | |
| upper Eocene | |
| Brule Formation | |
| lower Oligocene | |
| middle Oligocene | |
| Chadron Formation | |
| SN | In Wyoming, includes Chadron, Brule, and Arikaree formations. NE Colorado, E Montana, Nebraska, North Dakota, South Dakota, Wyoming. Upper Eocene to middle Oligocene. Age was previously considered Oligocene. Indexed with age as applicable. |