Colorado Area Code Information

Colorado Area Codes


Colorado Area Code Overlays
303 and 720


Colorado is currently using four area codes. Colorado has had two area code splits and one area code overlay plan, often called an overlay complex.

Area code 303 originally covered all of Colorado when it was established in 1947. It was not until 1988 that Colorado experienced sufficient growth in population and telephone use to need an additional area code. It was at that time that area code 303 was split to form area code 719. In 1995 area code 303 was split again to form area code 970. In 1998 area code 720 was put into use as an overlay of area code 303.

Today area code 303 and 720 covers central Colorado including Boulder and Denver. Area code 719 covers southeastern Colorado including  Pueblo and Colorado Springs. Area code 970 covers northern and western Colorado including  Aspen, Durango, Grand Junction and Fort Collins.


Changes and History of Colorado Area Codes:

01/01/1947
Area code 303 was put into service.  In 1988 Area code 303 was split to form area code 719. In 1995 area code 303 was split to form area code 970. In 1998 area code 303 was overlaid with area code 720.

03/05/1988
Area code 719 was put into service. Area code 719 was created from a split of area code 303.

04/02/1995
Area code 970 was put into service. Area code 970 was created from a split of area code 303.

06/01/1998
Area code 720 was put into service. Area code 720 is an overlay of area code 303.

Colorado Area Code Map