Undercutting of the bank along the Gros Ventre Road has Grand Teton National Park officials uncertain when the road will reopen to traffic/NPS

With runoff still pouring out of the Gros Ventre Range just east of Grand Teton National Park, erosion cutting away at the Gros Ventre/Kelly Road has park officials unsure when they can reopen it to traffic.

According to the Natural Resources Conservation Service, the snowpack in the Gros Ventre Range and other areas that melt into the Gros Ventre River system received the highest amount of precipitation this past winter compared to the last 36 years. Earlier this month, erosion caused by the river forced 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.

Park officials now say the closed portion of the road is expected to open to alternating one-lane of traffic within the next two weeks. Park engineers, in consultation with subject-matter experts with the Federal Highway Administration and a local geotechnical firm, are assessing the road and nearby erosion, and believe one-lane traffic can be safely and efficiently managed through the currently closed section of roadway. The plan includes an automated traffic signal that will alternate eastbound and westbound one-way traffic for vehicles and bicycles.

Wyoming Department of Transportation and Teton County Engineering/Roads Department have also been involved with consulting and providing road barriers in response to this incident.

The highest snowpack in nearly four decades is fueling runoff down the Gros Ventre River in Grand Teton National Park/NPS

"We plan to open the Gros Ventre Road as soon as we safely can to one-lane of traffic. We know the road closure has impacts to many, and we are doing our best to safely re-establish this vital transportation link within the park," said Grand Teton Superintendent David Vela.

The Gros Ventre/Kelly Road is located along the Gros Ventre River near the southern boundary of Grand Teton National Park. Currently, traffic to the community of Kelly and the Gros Ventre Campground, as well as other locations in the area, is rerouted via Antelope Flats Road. All detours are signed along the roadways.

More than 20 feet of the riverbank has eroded this spring due to substantial water runoff. The eroded river bank is immediately adjacent to a section of the road, located approximately two miles east of the Gros Ventre Junction. The National Park Service installed streambank armoring at this location to avert this from occurring in the past. However, the dynamic and braided nature of the river course changed quickly and dramatically this spring. Monitoring of the area will continue.

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.