OREGON CAVES NATIONAL MONUMENT

single cave comprising a series of chambers joined by subterranean corridors on four levels, in southwestern Oregon, U.S., in the Siskiyou Mountains near the California border. Established in 1909, the monument occupies an area of 488 acres (197 hectares). Formed by the dissolving of limestone by groundwater, the cave contains many beautiful stalagmites, stalactites, and other fantastic formations. On the surface above and around the caves are forests of Jeffrey pine, with many trees from 100 to 180 feet (30 to 55 m) high and from 200 to 400 years old.