Mount Tehama

From Wikipedia, the free encyclopedia

Brokeoff Mountain
Broken face of Brokeoff Mountain (winter photo)
Elevation	9,235 feet (2,815 metres)
Location	California, USA
Range	Cascades
Coordinates	40°26′43″N, 121°33′33″W
Topo map	USGS Lassen Peak
Type	Stratovolcano
Easiest route	Hike

Mount Tehama (also called Brokeoff Volcano) is an eroded andesitic stratovolcano located in the Shasta Cascade part of the Cascade Volcanic Belt and the Cascade Range in Northern California. Part of the Lassen volcanic center, its highest remaining remnant, Brokeoff Mountain, is itself the second highest peak in Lassen Volcanic National Park and connects to the park's highest point, Lassen Peak. The few hikers that summit this mountain each year are treated to amazing view of Lassen Peak, the Central Valley of California, and many of the park's other features. On clear days Mount Shasta can also be seen in the distance.

Tehama started life as some 600,000 years ago. At its peak, it would have reached approximately 3,350 meters (10,991 feet) high, with a diameter at the base of approximately 12 kilometers. Volcanic activity then declined 400,000 years ago, with other volcanic lava domes forming at the edges of Mount Tehama later on, the largest and best known of which is Lassen Peak. A combination of continued hydrothermal activity and erosion, particularly by glaciers during ice ages, removed the central cone of the volcano, leaving a large caldera, the northern edge of which can still be seen.

Other remnants of Mount Tehama include Mount Conard, Pilot Pinnacle, Mount Diller, and Diamond Peak.