Lava Flows

Future eruptions like those of the last 10,000 years will probably produce deposits of ash, lava flows, domes, and pyroclastic flows, and could endanger infrastructure that lie within several tens of kilometers of the volcano.

Many lava flows and one cinder cone erupted at several vents between 10,000 and about 2,000 years ago.

Mount Shasta is located in the Cascade Range in northern California about 65 km (40 mi) south of the Oregon-California border. One of the largest and highest (14,162 ft) of the Cascade volcanoes, the compound stratovolcano is located near the southern end of the range that terminates near Lassen Peak.

Mount Shasta erupts episodically with ten or more eruptions occurring in short (500-2,000 year) time periods separated by long intervals (3,000-5,000 years) with few or no eruptions. Evidence suggests that magma most recently erupted at the surface about 3,200 years ago.

Shastina is a large subsidiary cone that rises to 3,758 m (12,330 ft) and lies on the flank of Mount Shasta, 3 km (1.8 mi) west of the volcano's summit.

Black Butte is a group of overlapping dacite domes about 13 km (8 mi) west of Mount Shasta.

Hotlum cone forms the summit and the north and northwestern slopes of Mount Shasta.