The Slumgullion Earthflow is a remnant of a landslide in the San Juan Mountains in Hinsdale County, Colorado.
[1][2][3] 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.
[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.