RIFLE, Colo. (AP) - A recent 3.3 magnitude earthquake was the largest to hit a western Colorado county in a decade.
The U.S. Geological Survey told the Rifle Citizen Telegram that seven people reported the earthquake that shook Garfield County towns on Monday afternoon. The quake came a week after 11 small earthquakes hit the Marble area and followed a 2.9 magnitude earthquake recorded in New Castle on Christmas Day.
After the Christmas quake, an activist group asked state oil and gas regulators to determine whether the earthquakes are related to nearby injection wells. Such wells have been linked to quakes in Oklahoma, but the wells in Garfield County are not of the volume found to cause seismic activity.
National Earthquake Information Center geophysicist Julie Dutton said she doubts any such connection in Garfield County.