<Tr> <Th> Designated </Th> <Td> </Td> </Tr> <P> The Slumgullion Earthflow in the San Juan Mountains in Hinsdale County, Colorado has been a National Natural Landmark since 1983 . It is also a Colorado Natural Area and an Area of Critical Environmental Concern . </P> <P> The earthflow, a slow moving landslide, crawled down the valley about 700 years ago creating the 4 miles (6.4 km) long and 2,000 feet (610 m) wide mass . The earthflow lies a few miles south east of Lake City . The landmark site covers 1,291 acres (522 ha) and is owned 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)." Lake San Cristobal was dammed by the earthflow . A second earthflow has been moving continuously for about 300 years over older stable rock . It moves at a rate of about 7 meters (23 feet) per year . </P> <P> The area is a habitat for elk and deer . </P>

What type of mass movement is the slumgullion slide