A 5.8-magnitude earthquake that hit western Montana early Thursday morning was felt from Missoula to Billings and some surrounding states.
The quake's epicenter was about 6 miles south of Lincoln, originating from a depth of nearly 3 miles underground, according to a preliminary report from the U.S. Geological Service.
The USGS recorded seven more tremors in the same area within an hour of the initial quake, and they ranged in magnitude from 4.9 to 3.8
The 12:30 a.m. earthquake was strong enough to knock items off of walls and shelves in Helena and Missoula. Lewis and Clark County Sheriff Leo Dutton said Lincoln lost electricity as a result of the quake, but the power has since been restored.
Lisa Large, a bartender at the Wheel Inn Tavern in Lincoln, said the power went out and bottles flew off the shelves when the earthquake hit. Other than that, she said, there wasn’t any major damage there. She was in a fairly jovial mood when called by a Missoulian reporter near closing time at 1:50 a.m.
“It slopped all the grease outta the fryer,” she said. “The kitchen’s a mess right now. The lights have been out and they just came back on. Hopefully we don’t get any more aftershocks.”
Dutton said the fire chief in Lincoln was sending people out to check for damage, but they have not found any yet.
Missoula Police Department Corporal Mick McCarthy said the department has had calls from people asking what was going on with the earthquake and some medical calls, but no power outages reported or gas leaks.
"No property damage reported yet, but it's still early," McCarthy said.
Dave Eplin from Deer Lodge called The Montana Standard shortly after 12:30 a.m. asking for confirmation of an earthquake.
“I was lying in bed with my wife reading and all of a sudden the whole house shook,” he said. “At first I thought it was the wind, but it wasn’t the wind. I’ve checked to see if my pilot lights were still on and they are.”
Twitter lit up around Montana seconds after the quake, with people weighing in from Bozeman to Kalispell to Glacier National Park to Billings and elsewhere in Montana.
"Did the entire state of Montana just have an earthquake?" tweeted Brandon Furr.
Sean Ryan of Butte tweeted, "Now that everyone in Montana is awake from that earthquake ... you guys want to play Monopoly or something?"
Glacier National Park account tweeted, "Western Montana just had a decent-sized earthquake. Good shake here at Park HQ in West Glacier #geology."
Minor earthquakes are fairly common, although Thursday's moderate quake was the strongest felt in western Montana in several years. The last one to exceed 5.0 magnitude was reported 12 years ago near Dillon, according to the USGS. Most of those incidents had epicenters farther south, many centering in the famously active Yellowstone National Park.
Mike Stickney, seismologist at the Earthquake Studies Office, Montana Bureau of Mines and Geology on the Montana Tech campus in Butte, said the quake was probably the strongest in Montana since October 1964.
The location, he said, is not surprising. “It’s right along the axis of the intermountain seismic belt.”
He said the quake occurred on a strike/slip fault, a vertical fault where one side moves horizontally against the other, similar to the kind of movement experienced along the San Andreas Fault in California.
He said he does not believe the quake is seismically tied to the recent “swarm” of smaller earthquakes in the Yellowstone National Park area. “I don’t see any direct relationship between these two sequences,” he said.
“This is a pretty sizeable earthquake. It would certainly have the potential to do structural damage near the epicenter, but we’ve had no reports indicating damage yet.”
The USGS reports the Lincoln quake was one of 20 within the last week and 236 within the last month.
Within an hour of the Lincoln quake, more than 5,000 people had reported feeling the shake, filling out surveys the scientists use to document reach and strength.
Most people across the region reported category III or IV movement, which typically includes brief shaking that rattled some items without knocking them from shelves. Some reports from Helena and Bonner were initially classified as category 5, which can include some shifted furniture or light damage. A handful of reports from Lincoln and the immediate area were initially classified as category VII, which can include structural damage to buildings, though none has been confirmed.
The 911 dispatch center in Helena has asked that people stop calling 911 to report the earthquake unless they have an actual emergency.
This story will be updated.