Medicine Lake Volcano
| Medicine Lake Volcano | |
|---|---|
Medicine Lake volcano as seen from Lava Beds National Monument | |
| Highest point | |
| Elevation | 7,921 ft (2,414 m) NAVD 88 |
| Coordinates | 41°36′39″N 121°33′13″W / 41.610956028°N 121.553635458°W |
| Geography | |
| Location | Siskiyou County, California, U.S. |
| Parent range | Cascade Range |
| Topo map | USGS Medicine Lake |
| Geology | |
| Rock age | about 500,000 years |
| Mountain type | Shield volcano |
| Volcanic arc | Cascade Volcanic Arc |
| Last eruption | 1080 ± 25 years |
| Medicine Lake | |
|---|---|
The lake with Mount Shasta in the background | |
Bathymetric map | |
| Location | California |
| Coordinates | 41°34′54″N 121°35′56″W / 41.58167°N 121.59889°W |
| Basin countries | United States |
| Max. length | 0.6 mi (1 km) |
| Max. width | 1.2 mi (2 km) |
| Surface area | 0.64 sq mi (1.65 km2) |
| Average depth | 24.0 ft (7.3 m) |
| Max. depth | 152 ft (46.4 m) |
| Water volume | 470,000,000 cu ft (13,400,000 m3) |
| Shore length1 | 20,384 ft (6,213 m) |
| References | |
| 1 Shore length is not a well-defined measure. | |
Medicine Lake Volcano is a large shield volcano in northeastern California about 30 mi (50 km) northeast of Mount Shasta. The volcano is located in a zone of east–west crustal extension east of the main axis of the Cascade Volcanic Arc and the Cascade Range. The 0.6 mi (1 km) thick shield is 30 mi (50 km) from east to west and 50 mi (80 km) from north to south, and covers more than 800 sq mi (2,200 km2). The underlying rock has downwarped by 0.3 mi (0.5 km) under the center of the volcano. The volcano is primarily composed of basalt and basaltic andesite lava flows, and has a 4 by 7 mi (7 by 12 km) caldera at the center.
The Medicine Lake shield rises about 3,900 ft (1,200 m) above the Modoc Plateau to an elevation of 7,795 ft (2,376 m). Lavas from Medicine Lake Volcano are estimated to be at least 140 cu mi (600 km3) in volume, making Medicine Lake the largest volcano by volume in the Cascade Range (Newberry Volcano in Oregon has the second largest volume). Lava Beds National Monument lies on the northeast flank of the volcano.
Medicine Lake Volcano has been active for 500,000 years. The eruptions were gentle rather than explosive like Mount St. Helens, coating the volcano's sides with flow after flow of basaltic lava. Medicine Lake is part of the old caldera, a bowl-shaped depression in the mountain. It is believed that the Medicine Lake volcano is unique, having many small magma chambers rather than one large one.
The Medicine Lake Highlands are largely managed by the United States Forest Service as part of Klamath, Shasta–Trinity, and Modoc National Forests. In 2025, President Joe Biden established Sáttítla Highlands National Monument to protect the area from development.