The Town of Erie is a Statutory Town in Boulder and Weld counties in the U.S. state of Colorado. The population as of the 2010 census was 18,135, up from 6,291 at the 2000 census. Erie is located just west of Interstate 25, with easy access to Interstate 70, Denver International Airport and Colorado's entire Front Range. Erie's Planning Area spans 48 square miles (120 km²), extending from the north side of State Highway 52 south to State Highway 7, and between US 287 on the west and Interstate 25 to the east.