Craters of the Moon Volcanic Field


Craters of the Moon volcanic field lies at the northwest margin of the Idaho's eastern Snake River Plain.


The northern part of the Craters of the Moon laps up against the White Knob and Pioneer Mountains. As the largest volcanic field in the region, it covers about 1600 km2 (620 mi2) and contains more than 60 discernible lava flows that were erupted from one fissure system during eight episodes over the past approximately 15 k.y. About 25 cinder cones, up to 250-m (820-ft) high, formed primarily along a 45-km-long (28-mi-long) segment of the Great Rift volcanic rift zone, the principal 2-8 km (1.2-5 mi) wide fissure system that trends northwest to southeast through Craters of the Moon National Monument. The eight eruptive episodes that formed the field occurred between about 15,000 and 2,000 years ago and were separated by quiescent periods averaging about 2,000 years in duration. The Craters of the Moon volcanic field is a polygenetic group of lava flows, meaning that it erupted multiple times. This contrasts with other Snake River Plain lava fields, which were formed during single eruptive episodes of relatively short duration; they are monogenetic lava fields.


Date published: February 4, 2019

Craters of the Moon: Idaho's last (and next?) volcanic eruption

Idaho is home to several young volcanoes, including the Craters of the Moon, Wapi, Kings Bowl, North and South Robbers, Cerro Grande, Hells Half Acre, and Shoshone lava fields. Craters of the Moon is one of the youngest volcanic areas in Idaho and may be the most likely in the state to erupt again.

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