June 27, 1925 - Clarkston Valley, MT - M 6¾
The Clarkston Valley, Montana earthquake occurred at 6:21 p.m. local time on June 27, 1925. The epicenter was located approximately 8 miles north of Three Forks, MT just north of Yellowstone Park. It was reported felt over nearly two-thirds of the state (approximately 1,000,000 square kilometers) – as far west as Seattle, WA to the eastern Montana/South Dakota border, as far north as Thermopolis and Casper, WY and south to Spokane, WA.
Some buildings in areas near the epicenter were badly damaged. Buildings and pavement were cracked. Chimneys toppled. Windows shattered in some locations. Plaster was shaken from walls and merchandise fell from store shelves.
The heaviest damage in terms of quantity and severity was reported in Three Forks, Manhattan and White Sulphur Springs with some buildings being reduced to rubble. There were also reports of extensive damage to the town of Willow Creek, including reports that the town was in flames. Broken wire connections prevented communication to confirm these reports. It was later learned that damage in Willow Creek was slight.
Some individuals rushed into the streets, fainted or were knocked to the ground from the shaking, but no loss of life was reported. A woman sustained a broken leg (also reported as a broken hip) as she fell while rushing out of her home. Additional reported injuries were limited to bruises and cuts due to broken glass and falling materials. Many individuals were too nervous to sleep and some preferred to sleep out of doors.
The earthquake triggered several landslides and rockslides. Three passenger trains were stranded when rockslides blocked rail lines. There were also reports of rail tunnels caving in. And some concern was reported about the safety of area bridges. A number of ground cracks and fissures were reported in areas closest to the epicenter. There were also reports of increased flow at some springs in the area.
It was reported that the day following the earthquake, thousands of visitors from nearby towns and cities flooded into Manhattan and Three Forks to survey the damage.
For additional information about this earthquake:
Earthquake Summary Newspaper Articles Photos Additional Resources
Intermountain Seismic Belt Historical Earthquake Project
- Intermountain Seismic Belt Historical Earthquake Project Main Page
- 1945 Flathead Lake, MT M5.5
- 1952 Bigfork, MT M5.5
- 1935 Helena, MT (series) M6¼
- 1928 Helena, MT M 5 ½ ±
- 1929 Lombard, MT M 5.6
- 1925 Clarkston Valley, MT M 6¾
- 1947 Virginia City, MT M 6¼
- 1959 Hebgen Lake, MT M 7.5
- 1975 Yellowstone National Park , WY M 6.1
- 1945 Central Idaho M 6.0
- 1944 Central Idaho M 6.1
- 1983 Borah Peak, ID (series) M 7.3
- 1905 Shoshone, ID M 5½ ±
- 1994 Draney Peak, ID M 5.9
- 1930 Grover, WY M 5.8
- 1975 Pocatello Valley, ID M 6.0
- 1962 Cache Valley, UT M 5.7
- 1884 Bear Lake, ID M 6.3
- 1909 Hansel Valley, UT M 6±
- 1934 Hansel Valley, UT (series) M6.6
- 1914 Ogden, UT M 5½ ±
- 1894 Ogden, UT M 5.0
- 1910 Salt Lake City, UT M 5½±
- 1949 Salt Lake City, UT M 5.0
- 1943 Magna, UT M 5.0
- 1962 Magna, UT M 5.2
- 1958 Wallsburg, UT M 5.0
- 1915 Provo, UT M 5.0
- 1900 Eureka, UT M 5½ ±
- 1876 Moroni, UT M 5.0
- 1961 Ephraim, UT M 5.0
- 1988 San Rafael Swell, UT M 5.3
- 1989 So. Wasatch Plateau, UT M 5.4
- 1901 Southern Utah M 6½±
- 1945 Glenwood, UT M 5.0
- 1910 Elsinore, UT M 5.0
- 1921 Elsinore, UT (series) M 6±
- 1967 Marysvale, UT M 5.2
- 1908 Milford, UT M 5.0
- 1959 Panguitch, UT M 5.0
- 1933 Parowan, UT M 5.0
- 1942 (Aug) Cedar City, UT M 5.0
- 1942 (Sept) Cedar City, UT M 5.0
- 1902 Pine Valley, UT (series) M 6
- 1992 St. George, UT M 5.8
- 1891 St. George, UT M 5.0
- 1887 Kanab, UT M 5.7
- 1959 Kanab, UT M 5.7