JACKSON, Wyo. — Next month will mark the 100th anniversary of the Gros Ventre Slide, and Bridger-Teton National Forest (BTNF) will be hosting a stewardship and educational event to commemorate the event.

BTNF is inviting the public to attend the event on Saturday, June 7, which is National Trails Day. From 9 a.m. to 12 p.m., attendees will help with trail maintenance, sign installations and facility upkeep at the Gros Ventre Slide Geological Area. The day will culminate with a special program from 12 to 2:30 p.m. discussing the historical context of the massive landslide that formed Lower Slide Lake.

The event is free to attend, and BTNF is asking for those interested in attending to RSVP by Wednesday, June 4, by calling Hannah Jacobsen at 307-739-5587, or emailing hannah.jacobsen@usda.gov. Guests are welcome to participate in one or both parts of the event.

The Gros Ventre Slide occurred on June 23, 1925. According to the Forest Service website, the landslide was caused by “a complex combination” of underlying geology, a thick snowpack, heavy rainfall and the position of the river below. Around 4 p.m. that day, the slide sent 50 million cubic yards of rock, trees and debris hurtling down the north face of Sheep Mountain.

The landslide formed an earthen dam that blocked the flow of the Gros Ventre River and created Lower Slide Lake. It wasn’t until nearly two years later, in May 1927, that the dam broke from a surge of spring snowmelt and runoff, flooding the town of Kelly, and killing six people and hundreds of livestock.

Monica is a Staff Reporter who studied journalism at Syracuse University and has been in the valley since 2015. She loves writing about the local food and bev scene, especially craft beer. When she’s not on the clock, you can find her paddle boarding, sewing, or whipping up a new recipe at home.