Early morning Western Montana quake wakes up Ravalli, St. Ignatiu – KYSS-FM

Ravalli and St. Ignatius residents were rattled awake this morning by another earthquake, the second to be recorded along a fault line north of Ravalli this fall. 
Initial readings from the U.S. Geological Survey showed the quake at a 3.7 magnitude, with the epicenter at a depth of 7.4 miles under the hills northeast of Ravalli and southwest of St. Ignatius. The quake happened at 6:47 this morning. 
Residents were initially reporting they had felt the quake over a broad area from the north side of Missoula north to Polson, with a few reports even as far north as Kalispell. 
More than 300 people have reported feeling the quake according to USGS tracking data. 

That's in the same general area as another quake, magnitude 3.2 that hit the same fault line on Friday, October 14th. That quake was in the evening and not noticed by as many people.
There was also a slightly smaller quake, a magnitude 2.9 quake north of Big Arm in September. 
These latest quakes around the Mission Valley come after several years of inactivity in that area. A series of similarly sized earthquakes happened in that same general region more than a decade ago. Geologists say Western Montana is a very active area for earthquakes, with multiple fault lines around the region. Many of those have never been completely mapped because of a lack of funding. However, agencies do have a good idea of where they are, and continually map smaller quakes like the ones in Lake County. 
If you felt today's quake you can report that experience to the USGS which helps with the quake research.