Craters of the Moon

Craters of the Moon, the largest lava field of the Snake River Plain (SRP), covers about 1,600 km2 with more than 60 mapped lava flows erupted from eight fissure systems. About 25 cinder cones up to 250 m high formed primarily along a 45-km-long segment of the Great Rift, the principal 2-8 km wide fissure system that trends NW-SE through Craters of the Moon National Monument. Craters of the Moon lies at the NW part of the eastern SRP, with White Knob and the Pioneer Mountains along the northern boundary. The lava field was formed during eight eruptive episodes between about 15,000 and 2,000 years ago separated by quiescent periods up to about 3,000 years in duration. This contrasts with other SRP lava fields, which were formed during single eruptive episodes of relatively short duration. A complex assemblage of basaltic volcanic features is present, and cinder cones are common.