Montanans Count the Aftershocks

Eight aftershocks rumbled through southwestern Montana early Tuesday after a 6.5 magnitude earthquake rattled windows, buildings and nerves but caused no serious damage.

The U.S. Geological Survey said the late Monday earthquake and its aftershocks were centered about 13 miles northeast of Dillon, although residents across a wide swath of Montana, Idaho and Washington reported feeling the main temblor about 10:10 p.m.

Reports came in from as far away as Seattle, about 500 miles to the west; Hardin, about 250 miles to the east; Troy, about 250 miles to the north; and Bonners Ferry, Idaho, about 300 miles to the south.

Some residents reported two distinct tremors, several seconds apart, lasting about eight to 10 seconds in all.

The aftershocks measured 2.8 to 3.8 and occurred from 10:30 p.m. Monday to 6:45 a.m. Tuesday, the geological agency said.

In Dillon, Beaverhead County Commissioner Mike McGinley said there were scattered reports of broken glass and other minor damage around town. Bricks had fallen off several buildings and chimneys, but the quake’s epicenter was on an old geologic fault line with “no population in the area,” Chief of Police John Gutcheck said.