Fort Rock–Christmas Lake Valley basin
Fort Rock–Christmas Lake Valley basin | |
|---|---|
Fort Rock and its basin | |
| Coordinates: 43°18′N 121°00′W / 43.3°N 121°W | |
| Location | Lake County, Oregon, United States |
| Age | About 50,000 to 100,000 years old |
| Elevation | 4,331–5,630 ft (1,320–1,716 m) |
| Last eruption | About 50,000 years ago |
Fort Rock–Christmas Lake Valley is a basin of a former inland sea that existed in that region from Pliocene through late Pleistocene time.
The Fort Rock basin maar field includes over 30 hydrovolcanic landforms spread over an area of 1,500 square miles (4,000 km2). During the Pleistocene and early Holocene, Paleolake Fort Rock encompassed the entire basin.