The first record of an earthquake in Minnesota was in 1860. Although the exact date is unknown, the shock was fairly strong in the central part of the State. Very little information is available about this earthquake.
On September 3, 1917, another earthquake shook the central part of Minnesota. Intensity VI (Modified Mercalli scale) effects were noted at Staples. The shock was also felt at Brainerd, about 30 miles east of Staples.
Several tremors located outside of Minnesota have been felt within the State's borders.
On November 15, 1877, two earthquakes 45 minutes apart occurred in eastern Nebraska. The shocks caused damage at North Platte and Columbus, Nebraska and at Sioux City, Iowa. The felt zone encompassed an elliptical area roughly 600 by 300 miles, including the southwestern part of Minnesota.
A strong earthquake centered in Illinois occurred on May 26, 1909, affecting an area of approximately 500,000 square miles, includings parts of Minnesota. Intensity VII effects were noted over a considerable area from Bloomington, Illinois to Platteville, Wisconsin. Many chimneys fell at Aurora, Illinois. Although details ae lacking, this shock was probably felt at intensity IV or V in southeastern Minnesota.
A strong earthquake on February 28, 1925, centered in the St. Lawrence River region near La Malbaie, Quebec, Canada, was felt widely in the Northeastern United States. The shock was lightly felt at Minneapolis.
Ten years later, on November 1, 1935, another strong earthquake occurred near Timiskaming, Canada and was felt over an area of the United States estimated at one million square miles. This tremor was also lightly felt at Minneapolis.
A recent earthquake to affect Minnesota occurred on November 9, 1968. Centered in south-central Illinois, the earthquake was felt over approximately 580,000 square miles of the Central United States. Minor damage was reported at Chicago, Illinois; Evansville, Indiana; and St. Louis, Missouri, as well as from a number of cities and towns in the epicentral area. Intensity I-IV effects were noted in Minnesota at Austin, Glencoe, Mankato, Minneapolis, Rochester, and St. Paul.
Abridged from Earthquake Information Bulletin, Volume 6, Number 1, January - February 1974, by Carl A. von Hake.
For a list of earthquakes that have occurred since this article was written, use the Earthquake Search.