The earthquake was recorded in Dacono, about 30 miles north of Denver, around 6 a.m. and was felt by hundreds of people, according to the Geological Survey.

A rare earthquake jolted the northern suburbs of Denver, in the area of the Mile High City, just after sunrise, catching many Colorado residents completely off guard.

There hasn’t been a magnitude 3 or larger earthquake in the Denver metro area since 1981, when a magnitude 4.3 earthquake occurred in Northglenn, the USGS said. The USGS said Fr