The monument, located between
Modoc National Forest and
Klamath National Forest in northern California near the Oregon border, is the result of lava that erupted from Medicine Lake volcano centuries ago. Covering 46,500 acres, the monument is characterized by cinder cones, deep chasms and more than 300 lava tube caves of various sizes.
A visitor center interprets the history and geology of the area. Open daily year round. There is an admission charge to the monument of $5 per vehicle.