According to the USGS, an earthquake that measured 4.0 on the Richter Scale rattled the western parts of Wyoming at about 11:30 PM last night. The epicenter was described as being 14 miles WNW of Afton, Wyoming and was approximately 3 miles deep. Reports are coming in that it was felt in Kemmerer, Wy and Pocatello, Idaho. No reports of damage have been received.