Sites to See Yellowstone National Park Grand Teton National Park Harriman State Park Henry's Lake State Park Craters of the Moon Mesa Falls Local Attractions Craters of the Moon National Monument Area Map The Craters of the Moon was established as a national monument in 1924. This strange land was created, not by meteors, but by volcanoes and flowing lava. The lava field covers 618 square miles and is the largest young basaltic lava field in the continental US. The monument preserves 83 square miles. The park contains more than 20 volcanic cones and there are 60 different lava flows on the surface, ranging in age from 15,000 years to 2,000 years old. © Copyright 2008 Rexburg Chamber of Commerce. All Rights Reserved.