Historic Earthquakes

Near Sheep Mountain, southwest Idaho
1944 07 12 19:30 UTC
Magnitude 6.1
Intensity VII

This earthquake apparently was most severe in the area of Fontez Creek, near Sheep Mountain, Idaho, where buildings were shaken so severely that occupants thought the structures were falling apart. A new cabin set on concrete piers was displaced on its foundation. Along Seafoam Creek, rocks and boulders were thrown down the hillside.

Cracks about 30.5 meters long formed in the ground in the Duffield Canyon trail along Fontez Creek. Cracks 2.5 to 7.5 centimeters wide extended for several meters in a continuous break near Seafoam. A section of the Rapid River Canyon Wall (near Lime Creek) fell into the river. Also felt in Montana, Oregon, and Washington. Seventeen shocks were reported felt, the first of which was the strongest.

Abridged from Seismicity of the United States, 1568-1989 (Revised), by Carl W. Stover and Jerry L. Coffman, U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, Washington: 1993.

See also Summary of Central Idaho 1944 Earthquake for more information.