Area Code 307 History:
Area code 307 was put into service.
The entire state of Wyoming uses area code 307.
Major cities or places in Wyoming within area code 307 include:
Area code 307 serves the larger cities and communities of Casper, Cheyenne, Cody, Evanston, Gillette, Green River, Jackson, Laramie, Rawlins, Riverton, Rock Springs and Sheridan in addition to many smaller communities throughout Wyoming.