Historic Earthquakes

Hebgen Lake, Montana
1959 08 18 06:37:15 UTC (local 08/17)
Magnitude 7.3
Intensity X

Largest Earthquake in Montana

Damage Photos

Damage Photos: 1   2   3

Photo of earthquake
Fault scarp and moat at Cabin Creek. Gallatin County, Montana. 1959.

Photo of earthquake
Red Canyon fault scarp near Red Canton Creek. Man present in picture. Nineteen foot displacement measured. Man for scale. Gallatin County, Montana. August 1959.

Photo of earthquake
Sand spout (Sand Volcano) at Parade Rest Ranch. At the time of the earthquake small fractures opened in the ground, and water and sand spewed out. During the earthquake, the tremors compacted the sand and gravel fill, and ground water which occupied the pores and interstices, was put under great pressure. As cracks formed in the sand and gravel normal to earthquake wave motion of repeated compression and expansion, water and sand were forced out through the cracks. Gallatin County, Montana. August 1959.

Photo of earthquake
Landslide-broken road. Hebgen lake. Gallatin County, Montana. August 1959.

Photo of earthquake
The Red Canyon fault scarp where it cuts through Blarneystone Rance. House sits on down thrown block; fault scarp here is 10 to 12 feet high. A small collasped shed (green roof) is on the up-thrown block. Gallatin County, Montana.

Photo of earthquake
The north end of Earthquake Lake. The trees to a level of about 50 feet above the present surface of Earthquake lake were once inundated for about 30 days while the Corps of Engineers constructed a new spillway across the Madison slide. The water was then let down to its present level. During this time the trees below the water level died and the water mark is clearly visible as a dark gray line. Montana. August 1959.

Photo of earthquake
Small longitudinal step fault scarps formed along the trace of Hebgen fault. View is northward, and these small step faults are along the south flank of Mount Hebgen, about half a mile northeast of Hebgen Dam. All scarps are in colluvium. Gallatin County, Montana. August 1959.

Photo of earthquake
Earthquake Lake showing both its present level, and its former level marked by a zone of dead needles. Partly submerged house still shows in center. Montana. August 1959.

Damage Photos: 1   2   3

Photos from the Earth Science Photographs from the U.S. Geological Survey Library, by Joseph K. McGregor and Carl Abston, U.S. Geological Survey Digital Data Series DDS-21, 1995.