Crooked River caldera
| Crooked River caldera | |
|---|---|
  Crooked River caldera | |
| Highest point | |
| Coordinates | 44°18′N 120°54′W / 44.3°N 120.9°W |
| Geography | |
| Location | Deschutes, Crook, and Jefferson counties, Oregon, U.S. |
| Parent range | Ochoco Mountains |
| Geology | |
| Rock age | 29.5 Ma |
| Mountain type(s) | Caldera, supervolcano |
| Last eruption | 29.5 million years ago |
The Crooked River caldera is a large ancient volcano and vent complex that straddles three central Oregon counties. The diameter of the caldera is about 41 by 27 kilometres (25 mi × 17 mi). It is notable for the welded tuff present at Gray Butte, Smith Rock, Powell Buttes, Grizzly Mountain and Barnes Butte. The volcano is considered extinct and last erupted about 29.5 Ma.[1]
References
- ^ McClaughry, Jason D.; Ferns, Mark L.; Gordon, Caroline L.; Patridge, Karyn A. (Fall 2009). "Field trip guide to the Oligocene Crooked River caldera: Central Oregon's Supervolcano, Crook, Deschutes, and Jefferson Counties, Oregon" (PDF). Oregon Geology. 69 (1). Oregon Department of Geology and Mineral Studies: 25–44. Retrieved 2025-12-20.