Craters of the Moon National Park

Craters of the Moon is a vast ocean of lava flows with scattered islands of cinder cones and sagebrush.

Craters of the Moon is in south-central Idaho, midway between Boise and Yellowstone National Park. The lava field reaches southeastward from the Pioneer Mountains. The rugged landscape of the monument is remote and undeveloped, with only one paved road across the northern end.

The Craters of the Moon Lava Field spreads across 618 square miles (1,601 km2) and is the largest mostly Holocene-aged basaltic lava field in the contiguous United States. The Monument and Preserve contain more than 25 volcanic cones, including outstanding examples of spatter cones. The 60 distinct solidified lava flows that form the Craters of the Moon Lava Field range in age from 15,000 to just 2,000 years old. The Kings Bowl and Wapi lava fields, both about 2,200 years old, are part of the National Preserve.

This lava field is the largest of several large beds of lava that erupted from the 53-mile (85 km) south-east to north-west trending Great Rift volcanic zone, a line of weakness in the Earth's crust. Together with fields from other fissures they make up the Lava Beds of Idaho, which in turn are in the much larger Snake River Plain volcanic province. The Great Rift extends across almost the entire Snake River Plain. The visitor centre is 5,900 feet (1,800 m) above sea level.