USGS: Colorado Experiences Largest Quake In More Than 40 Years

(CNN) -- A moderate 5.3-magnitude earthquake that rattled southern Colorado early Tuesday morning was the largest to hit the state in more than 40 years, the U.S. Geological Survey said.

The quake's epicenter was seven miles southwest of Cokedale, and 180 miles south of Denver. There were no immediate reports of casualties.A dispatcher at the sheriff's office in Las Animas County, which includes Cokedale, said the quake lasted almost 30 seconds.

The office received reports of rocks falling on a highway and of some structure damage.

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