Heavy runoff down the Gros Ventre River at Grand Teton National Park in Wyoming has forced the temporary closure of approximately 4.5 miles of the Gros Ventre/Kelly Road from the Gros Ventre Junction with U.S. Highway 26/89/191 to the Gros Ventre Campground due to significant erosion that is threatening the road.

This closure includes all vehicle and bicycle traffic. Traffic to the community of Kelly and the Gros Ventre Campground, as well as other locations in the area, has been rerouted via Antelope Flats Road. All detours are signed along the roadways. 

"The large amount of water flowing in the Gros Ventre River is causing some significant and accelerated erosion that may soon compromise the road," Grand Teton Superintendent David Vela said Tuesday. "The safety of anyone traveling that road is our first priority due to how fast the erosion has progressed in the last two days."

According to park staff, as of Tuesday afternoon the river bank had eroded more than 10 feet in 36 hours. An area closure has been implemented around the affected location.

The National Park Service will continue to monitor the situation and allow the dynamic system of the river to respond to the increased water flow. At this time, it is unknown how long the closure will be in effect and what the extent of the damage will be. It is anticipated the erosion will continue, as the water flow remains high and fast.

The Gros Ventre Campground is open and available for first-come, first-served overnight camping. During the road closure, access to the campground is via the Antelope Flats Road, which is approximately ½-mile north of Moose Junction. The Antelope Flats Road provides access to Mormon Row as well. There is no through vehicle traffic on Mormon Row or Warm Ditch Roads, although bicycles are allowed.