| McKay Formation | |
|---|---|
|  Stratigraphic range: Tortonian-Zanclean (Hemphillian) ~  | |
| Type | Formation | 
| Lithology | |
| Primary | Tuffaceous sandstone | 
| Location | |
| Coordinates | 45°30′N118°48′W / 45.5°N 118.8°W | 
| Approximate paleocoordinates | 45°24′N116°06′W / 45.4°N 116.1°W | 
| Region | Umatilla County, Oregon | 
| Country | United States | 
| Type section | |
| Named for | McKay Reservoir | 
The McKay Formation is a geologic formation in Oregon. It preserves fossils dating back to the Tortonian to Zanclean stages (Hemphillian) of the Neogene period. [1] [2] [3]
 
 
 
 The following fossils have been reported from the formation: [1] [4]