| Hanna Formation | |
|---|---|
| Stratigraphic range: Selandian-Thanetian (Torrejonian-Tiffanian) ~ | |
 Petrified wood from the Hanna Formation | |
| Type | Formation |
| Location | |
| Coordinates | 41°48′N 107°00′W / 41.8°N 107.0°W |
| Approximate paleocoordinates | 47°36′N 86°48′W / 47.6°N 86.8°W |
| Region | Wyoming |
| Country |  United States |
| Extent | Carbon Basin |
| Type section | |
| Named for | High Hanna Hill |
  Hanna Formation (the United States)  Hanna Formation (Wyoming) | |
The Hanna Formation is a geologic formation in Wyoming. It preserves fossils dating back to the Torrejonian to Tiffanian stages of the Paleogene period.[1]