The Gros Ventre landslide ( ) is in the Gros Ventre Wilderness of Bridger-Teton National Forest,

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. The Gros Ventre

landslide Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...

is east of

Jackson Hole Jackson Hole (originally called Jackson's Hole by mountain men) is a valley between the Gros Ventre Range, Gros Ventre and Teton Range, Teton mountain ranges in the U.S. state of Wyoming, near the border with Idaho, in Teton County, Wyoming, T ...

valley and

Grand Teton National Park Grand Teton National Park is a national park of the United States in northwestern Wyoming. At approximately , the park includes the major peaks of the Teton Range as well as most of the northern sections of the valley known as Jackson Hole. G ...

. The landslide occurred on June 23, 1925, following melt from a heavy snowpack, several weeks of heavy rain, and earthquake tremors in the area. Approximately of primarily

sedimentary Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...

rock slid down the north face of Sheep Mountain, crossed over the

Gros Ventre River The Gros Ventre River (''pronounced GROW-VAUNT'') is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed May 4, 2011 tributary of the Snake River in the state of Wyoming, USA. During i ...

and rode up the opposite mountainside a distance of . The landslide created a large

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

over high and wide across the Gros Ventre River, backing up the water and forming Lower Slide Lake. On May 18, 1927, part of the

landslide dam A landslide dam or barrier lake is the natural damming of a river by some kind of landslide, such as a debris flow, rock avalanche or volcanic eruption. If the damming landslide is caused by an earthquake, it may also be called a quake lake. Some ...

failed, resulting in a massive flood that was deep for at least downstream. The small town of Kelly, downstream, was wiped out, killing six people. It is one of the world's largest known examples of recent

mass wasting Mass wasting, also known as mass movement, is a general term for the movement of rock (geology), rock or soil down slopes under the force of gravity. It differs from other processes of erosion in that the debris transported by mass wasting is no ...

events aside from volcanic eruptions. Slide Lake is now much smaller than before the flood. Today, the landslide is partially reclaimed by the surrounding

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

but is still an obvious landmark from many vantage points in the Jackson Hole valley. It is easily accessible by traveling north from

Jackson, Wyoming Jackson is a resort town in Teton County, Wyoming, United States. The population was 10,760 at the 2020 census, up from 9,577 in 2010. It is Teton County's only incorporated municipality and county seat, and it is the largest incorporated town ...

or south from Moran, Wyoming and then taking the Antelope Flats road east off U.S. Route 26.

Etymology

In French, Gros Ventre means big belly / big stomach.

References

External links

* Natural disasters in Wyoming Landslides in the United States Geography of Teton County, Wyoming 1925 in Wyoming Bridger–Teton National Forest Landslide-dammed lakes 1920s landslides 1925 natural disasters {{Wyoming-geo-stub