Craters of the Moon

Craters of the Moon National Monument and Preserve protects an immense sea of black volcanic rock spread across the Snake River Plain of central Idaho. Its cinder cones, spatter cones, lava tubes, and frozen rivers of basalt erupted not from a single volcano but from the Great Rift, a deep crack in the Earth that has poured out lava in repeated episodes over the past 15,000 years, most recently about 2,000 years ago.

The landscape is so stark and lunar that NASA sent Apollo astronauts here in 1969 to study volcanic geology before going to the Moon. Established as a monument in 1924 and later greatly enlarged, it preserves one of the best-exposed basaltic volcanic fields in the country, where visitors can walk through lava tubes and climb cinder cones across a hauntingly barren, otherworldly plain.

• Idaho
  The Gem State, a rugged northern Rockies landscape related