February 29, 1928 - Helena ,MT - M 5½±
The 1928 Helena, Montana earthquake had no reported injuries or damage. The shaking startled people throughout the city of Helena and was more noticeable on upper floors of buildings with two or more stories above ground. The shaking was severe enough to disrupt a trial in one city courthouse. Without taking time to formally adjourn the proceedings, the judge and others fled the courtroom as the shaking began.
The earthquake was reported felt in areas southeast of Helena including: Trident, Three Forks, Manhattan, Logan, Lombard, and Sixteen-Mile Canyon. White Sulphur Springs, to the east of Helena, also reported earthquake shaking.
There were reports of shaken buildings, windows rattling, furniture moving, and goods being shaken from shelves.
For additional information about this earthquake:
Earthquake Summary Newspaper Articles
Intermountain Seismic Belt Historical Earthquake Project
- 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