Quake Lake is a lake in southwestern Montana in the United States. It was created after an earthquake struck on August 17, 1959, killing 28 people. Today, Quake Lake is deep and long. US 287 follows the lake and offers glimpses of the effects of the earthquake and landslide and visitor center is just off the road. The lake is mostly within Gallatin National Forest.The earthquakeThe earthquake measured 7.5 on the Richter magnitude scale (revised by USGS to 7.3) and caused an 80-million ton landslide, which formed a landslide dam on the Madison River. The earthquake was the most powerful to hit the state of Montana in historic times. The landslide traveled down the south flank of Sheep Mountain, at an estimated, killing 28 people who were camping along the shores of Hebgen Lake and downstream along the Madison River. Upstream the faulting caused by the earthquake forced the waters of Hebgen Lake to shift violently. A seiche, a wave effect created by wind, atmospheric pressure, or seismic activity on water, crested over Hebgen Dam, causing cracks and erosion.The earthquake created fault scarps up to 20ft high in the area near Hebgen Lake and the lake bottom itself dropped the same distance. 32000acres of the area near Hebgen Lake subsided more than 10ft. Several geysers in the northwestern sections in Yellowstone National Park erupted and numerous hot springs became temporarily muddied.