The Craters of the Moon National Monument is in the state of Idaho. It contains over 600 square miles of lava fields, making it the largest volcanic area in the lower 48 US States. It lies less than 300 miles from Yellowstone National Park, which is a highly active volcanic area. The super volcano, which is Yellowstone, erupts on roughly 600,000 year cycles. This volcanism is due to a hot spot in the earth’s crust, which brings hot molten rock very near to the surface. The North American tectonic plate is slowly sliding over this hotspot. It used to be under southern Idaho and Craters of the Moon. This area has been volcanic for many eons, but the lava flows that you see are quite recent in geologic terms. They are from 2000-15000 years old. The area is considered dormant, but not inactive.
The lava beds of Idaho were a hell on earth for early settlers on the Oregon Trail. It was impossible to traverse in a wagon. Many who ventured into this rocky and rugged area perished and were never heard from again. Those hearty few who explored the area gave the landmarks forbidding names, such as the Devil’s Orchard. This is an area of ancient twisted pines and up-shooting lava formations, called cinder crags, that they imagined as looking like trees.
The path to the south was more desirable, along the Snake River, but the area was inhabited by native Americans, who were not always friendly. Attacks in the 1850’s and 1860’s, such as those near Massacre Rocks, killed many settlers. To avoid conflict and the impassible lava beds, the settlers were motivated to find a northern route. In 1862, a guide, Tim Goodale, lead 1,095 emigrants in 338 wagons along a new route, through the foothills. This route was then named after him, as the Goodale Cutoff. It took the pioneers through mountainous terrain, but out of the danger of death by Indian raid or perilous journey through the lava fields. You can see the start of this detour in the northern part of the park.