When James Mauch learned about the collapse of a portion of Jackson Hole’s main roadway to Idaho, he was already working on a map of the region’s landslide susceptibility.
“It drives home for us the motivation of why we study geologic hazards in this part of the state,” said the Wyoming State Geological Survey researcher.
Teton County has been home to some of Wyoming’s most dramatic landslides. Kids in Kelly still sing about the 1925 Gros Ventre slide on Sheep Mountain that destroyed the town of Kelly, killed six people and created Slide Lake. The 2014 Budge Drive landslide that shuttered a Walgreens in Jackson and cost millions to stabilize. Then, in June 2024, the “Big Fill” slide carved out a section of Teton Pass, severing Jackson Hole from a large part of its workforce and leaving a three-hour long detour for the three week closure.
Mauch and his team in Laramie have released a new study that could help prevent future disasters.
The study offers a high-resolution map of landslide susceptibility across parts of Teton County. The interactive tool shows how slope angle and rock strength combine to create conditions ripe for deep-seated landslides. Those are slides that happen below the root level, Mauch said.
Thanks to legacy data from iconic geologist J.D. Love, who mapped the area in the 1960s, Mauch and his team were able to produce a much more granular view of the landscape.
They found that landslide susceptibility can change markedly over pretty short distances, Mauch said.
While the new map only accounts for slope and rock conditions, not external factors like rainfall or snowmelt, it’s a powerful starting point. The data are free to download, giving engineers, developers and local land managers a clearer picture of where it’s safest to build.
“We know that landslides will continue to occur in Teton County,” Mauch said. “But there are tools out there and resources to help minimize these adverse impacts, and this map is another tool to add to that list.”
