Colorado Area Code Directory Information

North American Numbering Plan assigned area codes, known initially as numbering plan areas, to US and Canada. The original plan was developed by AT&T and Bell Laboratories in the 1940s and implemented in 1947. This was done in order to make the telecommunications network of the region convenient. The three-digit area codes are part of every ten-digit phone number of the particular area. So each phone number of a designated area has the same first three digits. If you are dialing a number from the same area code as yours you need not dial the area code at all.

The US State of Colorado has 4 area codes. These are 303, 719, 720 and 970.

Area Code 303

According to the original North American Numbering Area Plan, area code 303 was the only one assigned to the State of Colorado. With the increase in population and the subsequent increase in telephone numbers, the area code was split up. In 1988, area code 719 came into being as the first split of area code 303 occurred. With another split, area code 970 became part of Colorado Area Code Directory in 1995. In 1998, area code 720 overlaid the area code 303.

The area code 303 covers areas like Boulder, Denver, and so on in the central region of the state. There are 17 counties under the area code 303. Some of them are Boulder, Jefferson, Park, Douglas, and Denver. There are 73 cities within the designated area. Some of them are Denver, Buffalo Creek, Jamestown, Wheat Ridge, Evergreen, Boulder, Aurora, Georgetown, Hudson, and others.

Area Code 719

The area code of 719 became part of the Colorado area code directory on March 5, 1988. The southeastern portions of the State of Colorado are under this area code. There are 30 counties within the area code 719. These include Cheyenne, Alamosa, Pueblo, Fremont, Crowley, and others. The area code covers 131 cities, some of which are Del Norte, Arlington, La Junta, Sheridan Lake, Florence, Westcliffe, Blanca, Weston, Colorado City, Pueblo, Rocky Ford, Holly, Monument, Woodland Park, and so on.

Area Code 720

On June 1, 1998, area code 720 officially overlaid the area code 303 in Colorado. This was done to ease the imminent telephone numbers shortage in the state. The area under area code 720 comprises 11 counties; some of these are Broomfield, El Paso, Adams, and Denver. The area code 720 covers 30 cities among which some are Idaho Springs, Colorado Springs, Henderson, Longmont, and so on.

Area Code 970

Covering northern and western parts of the State of Colorado is the area code 970. It was split from area code 303 on April 2, 1995. There are 37 counties within the boundaries of area code 970. Some of the counties within area code 970 are Albany, Morgan, Washington, Grand, La Plata, San Juan, Garfield, and so on. The cities within area code 970 number up to 199. Some of them are Almont, Fort Collins, Bedrock, Littleton, Grand Junction, Mesa Verde National Park, Somerset, and others.