Area Code 307 Location

Area code 307 is Wyoming’s lone, statewide area code, serving Casper, Wyoming and every town across the state. Created in 1947 as one of the original North American Numbering Plan codes, it has never been split or overlaid. Casper sits in central Wyoming along the North Platte River and is the state’s second‑largest city, known for Casper Mountain and its “Oil City” heritage. When you see a 307 phone number, it connects to life across Wyoming’s plains, mountains, and historic energy hubs.

Major cities and notable places in the 307 area code include:

• Cheyenne (state capital)
• Casper
• Laramie (home of the University of Wyoming)
• Gillette
• Rock Springs and Green River
• Sheridan
• Jackson and the Jackson Hole area
• Cody
• Riverton and Lander
• Landmarks: Yellowstone National Park, Grand Teton National Park, Devils Tower, the Bighorn Mountains, and the Wind River Range

As a single, statewide code, 307 is a point of pride in Wyoming culture and identity. Wyoming is in the Mountain Time Zone (MT), so 307 phone numbers align with Mountain Time. The code’s stability makes it easy to recognize calls from anywhere in the state, from ranch towns to national park gateways. “According to the North American Numbering Plan Administration (NANPA), area code 307 was assigned in 1947 and serves the entire state of Wyoming.”