Mount Spurr is a 3374 m high stratovolcano in the members of the Alaska Range Tordrillo Mountains in Alaska. It arose in the caldera of an older volcano, which has a diameter of up to 6 km and a height of 3000 m.
Mount Spurr has a second eruption vent next to the main peak with the Crater Peak, which has formed in a fraction of the old caldera. While the main peak has been inactive for more than 5,000 years ago, there were at Crater Peak last 1953 and 1992 outbreaks that resulted in ash rain down to 130 km east lying Anchorage.
The foot of Mount Spurr is covered by pyroclastic deposits with Eruptivgängen and volcanic sills, the flanks of the andesitic lava flows.
Named after the mountain Josiah Edward Spurr, a geologist of the United States Geological Survey, who led an expedition to the area in 1898. The proximity of Mount Spurr to trans-Pacific flight routes is potentially dangerous for air transport.
The Crater Peak with the main peak in the background