Craters of the Moon National Monument protects the largest basaltic lava field in the lower 48 states. The monument is filled with hundreds of unique volcanic formations, including lava tunnels, cinder cones, and ice caves, created by the heat and eruptions of the Great Rift. Though there have been no eruptions for several thousand years, the fascinating legacy of these formations has attracted geologists and visitors for decades.
While the monument was recently expanded to include two neighboring lava flows and nearly 1,000 square miles of terrain, most visitors will focus on the small developed area near the Visitor Center at the north end. A short loop drive provides panoramas of the stark environment, and short trails depart to unique formations and viewpoints. Informative signs talk about the unique geology and wildlife of the area.
Craters of the Moon National Monument is located in south central Idaho, along US 20 west of Arco.