| Bluff Formation | |
|---|---|
| Stratigraphic range: | |
 Bluff Formation at its type area, Bluff, Utah, US | |
| Type | Formation |
| Unit of | San Rafael Group |
| Underlies | Morrison Formation |
| Overlies | Summerville Formation |
| Thickness | 350 ft (110 m) |
| Lithology | |
| Primary | Sandstone |
| Other | Mudstone |
| Location | |
| Coordinates | 37°17′21″N 109°33′06″W / 37.2893°N 109.5518°W |
| Region | Four Corners |
| Country |  United States |
| Type section | |
| Named for | Bluff, Utah |
| Named by | Baker, Dane, and Reeside |
| Year defined | 1936 |
  Bluff Formation (the United States)  Bluff Formation (Utah) | |
The Bluff Formation is a geological formation found in the Four Corners area. It was deposited in the late Jurassic Period.