| Ojo Alamo Formation | |
|---|---|
| Stratigraphic range: Maastrichtian-Danian ~ | |
 Ojo Alamo Formation in the Bisti/De-Na-Zin Wilderness | |
| Type | Geological formation |
| Sub-units | Naashoibito Member, Kimbeto Member |
| Underlies | Nacimiento Formation |
| Overlies | Kirtland Formation |
| Lithology | |
| Primary | Conglomerate, sandstone, shale |
| Location | |
| Coordinates | 36°19′50″N 108°02′06″W / 36.3305764°N 108.0350723°W |
| Region | San Juan Basin, New Mexico |
| Country |  USA |
| Type section | |
| Named for | Ojo Alamo Spring |
| Named by | B. Brown |
| Year defined | 1910 |
The Ojo Alamo Formation is a geologic formation in New Mexico spanning the Mesozoic/Cenozoic boundary. Non-avian dinosaur fossils have controversially been identified in beds of this formation dating from after the Cretaceous–Paleogene extinction event, but these have been explained as either misidentification of the beds in question or as reworked fossils, fossils eroded from older beds and redeposited in the younger beds.