In the neighborhood of Deer Lodge several faults of apparently small extent that trend northwestward are mapped by the geologists of the Anaconda Copper Mining.

[2] The earthquake struck at 6:21 in the evening local time (June 28 at 01:21 UTC)[3] with the epicenter being located right near Townsend.

The earthquake had an intensity of IX (Violent), and was felt in Oregon, Idaho, Wyoming, Washington in the United States and British Columbia, Saskatchewan, Alberta in Canada.

[5] The shaking triggered landslides along the Missouri River which blocked railroad traffic for several weeks.

[6] Even though there were no deaths from the earthquake, at least two people were injured including a woman who broke her leg while rushing out of her home.