Hebgen Lake Earthquake 1959

At approximately 11:35 p.m. on August 17, 1959, a severe (M7.3 according to USGS) earthquake centered in western Montana rocked a five-state area. The greatest local force of the quake apparently centered in the Hebgen Lake-Madison River area within the Gallatin and Beaverhead National Forests.

It was known that many people were camped in the canyon below Hebgen Dam. This stretch of the Madison River is one of the most popular fishing and camping areas in Montana. With the lack of communications, the darkness, and access to the area blocked by slides it was impossible to appraise the situation immediately.
Initial rescue efforts were limited to campers helping each other.

Non Fire, Earthquake