Area Code 720 History:
Area code 720 was put into service. Area code 720 is an overlay of area code 303.
Counties in Colorado within area code 720 include:
Adams County, Arapahoe County, Boulder County, Broomfield County, Clear Creek County, Denver County, Douglas County, Eagle County, El Paso County, Elbert County, Gilpin County, Jefferson County, Park County, Sedgwick County, and Weld County.
Places in Colorado within area code 720 include:
Area code 720 serves Aurora, Boulder, Denver, Longmont and Westminster.
Major cities or places in Colorado within area code 720 include:
Area codes 303 and 720 serve central Colorado including the larger cities and communities of Aurora, Boulder, Brighton, Broomfield, Castle Rock, Castlewood, Columbine, Commerce City, Denver, Englewood, Highlands Ranch, Ken Caryl, Lafayette, Lakewood, Littleton, Longmont, Loveland, Northglenn, Parker, Southglenn, Thornton, Westminster and Wheat Ridge in addition to many smaller communities.