Aniakchak Crater

view of surprise lake from the rim of the aniakchak crater

Surprise Lake from the rim of Aniakchak Crater. NPS Photo

Quick Facts

Aniakchak National Monument, Alaska
One of the largest explosive craters in the world.
National Natural Landmark
Aniakchak Crater, located within Aniakchak National Monument, is one of the largest explosive craters in the world, averaging 6 miles wide and 2000 feet deep. The crater contains Surprise Lake, a warm springs fed lake that provides spawning grounds for a unique subspecies of salmon. The lake is the source of the Aniakchak River, which flows through a breach in the crater rim to the Pacific Ocean. The last eruption of this volcano was in 1931. It was designated in 1967, and is comprised of 20,727 acres.

Last updated: August 31, 2017