The earthflow, a slow-moving landslide, crawled down the valley about 700 years ago creating the 4-mile-long (6.4 km) and 2,000-foot-wide (610 m) wide mass.[1][2] The earthflow lies a few miles southeast of Lake City.[2] The landmark site covers 1,291 acres (522 ha) and is owned and managed by the US Forest Service and the Bureau of Land Management. It is "a striking example of mass wasting (the movement of large masses of earth material)." The Lake Fork of the Gunnison River was dammed by the earthflow, creating Lake San Cristobal.[1] A second earthflow has been moving continuously for about 300 years over older, stable rock.[3] It moves at a rate of about 7 meters (23 ft) per year.[4]
