Casper, Wyoming

Where Is Area Code 307?

Area code 307 serves the entire state of Wyoming, including Casper. Wyoming is in the Mountain West region of the United States, and 307 is the only area code assigned to the state.

Casper is one of the largest cities in area code 307, along with Cheyenne, Laramie, Gillette, Rock Springs, Sheridan, and Jackson. The area code covers all 23 Wyoming counties, including Natrona County, where Casper is located.

Area code 307 also covers major Wyoming landmarks and geographic features. These include Yellowstone National Park, Grand Teton National Park, Devils Tower, and parts of the Rocky Mountains. It also includes broad high plains, mountain basins, and energy-producing regions across the state.

History of Area Code 307

Area code 307 was established in 1947. It was one of the original area codes created by AT&T and the Bell System in the first North American Numbering Plan.

Area code 307 has never been split or overlaid. Wyoming has kept a single statewide area code because it has a small population and lower demand for new phone numbers than larger states.

Key Facts About Area Code 307

• Area code 307 is the only area code in the state of Wyoming.
• Casper, the reference city for this area code, is in Natrona County in central Wyoming.
• Area code 307 uses the Mountain Time Zone for most of the year, and Mountain Daylight Time during daylight saving time.
• Area code 307 was created in 1947 as one of the original North American area codes.
• Area code 307 serves all 23 counties in Wyoming.
• Wyoming had a population of 576,851 at the 2020 United States Census, and area code 307 covers that statewide population.
• Area code 307 includes the University of Wyoming in Laramie, the state’s flagship public university.
• Area code 307 covers major Wyoming destinations such as Yellowstone National Park, Grand Teton National Park, and Devils Tower National Monument.

Frequently Asked Questions

What state is area code 307 in?

Area code 307 is in Wyoming.

What major cities use area code 307?

Major cities in area code 307 include Casper, Cheyenne, Laramie, Gillette, Rock Springs, Sheridan, and Jackson.

Is area code 307 a toll-free number?

No. Area code 307 is a geographic area code for Wyoming.