The 307 area code is the single area code serving the entire state of Wyoming, the least populous state in the country. Assigned in 1947 as one of the original area codes, 307 has covered all of the Equality State on its own ever since and has become a proud badge of Wyoming identity.
Quick Summary of the 307 Area Code
| Area Code | 307 |
| State | Wyoming (WY) |
| Region | Statewide Wyoming |
| Major Cities | Cheyenne, Casper, Laramie, Gillette, Rock Springs, Sheridan, Jackson, Cody |
| Time Zone | Mountain Time (MT) – MST / MDT |
| Dialing Format | 7 or 10-digit dialing |
Geographic Coverage
The 307 area code is a statewide code covering all of Wyoming, including the state capital of Cheyenne in the southeast, the central oil city of Casper, the university town of Laramie, the energy hub of Gillette in the northeast, Rock Springs in the southwest, Sheridan in the north, and the resort town of Jackson and the frontier city of Cody near the Yellowstone gateway. It borders Montana, South Dakota, Nebraska, Colorado, Utah, and Idaho.
Time Zone
The 307 area code observes Mountain Time (MT). Clocks follow Mountain Standard Time (UTC−7) in winter and shift to Mountain Daylight Time (UTC−6) from mid-March through early November. All of Wyoming is on Mountain Time and observes daylight saving. From the West Coast, this region is one hour ahead of Pacific Time, so a 9:00 AM call in California reaches a 307 number at 10:00 AM local time.
Tip: Business hours across the 307 region generally run 9:00 AM to 5:00 PM local time, Monday through Friday.
How to Dial a 307 Number
Area code 307 is not part of an overlay, and as the only area code in Wyoming it has traditionally allowed 7-digit local dialing within the state. However, 10-digit dialing is now the recommended nationwide standard, and dialing the full 10-digit number (307 + the seven-digit line number) always works reliably. For international callers, dial your country’s exit code, then +1 (the North American country code), then 307, followed by the seven-digit local number.
Scam Alerts for the 307 Area Code
Like every U.S. area code, 307 has been used by scammers who spoof local numbers to appear trustworthy. Residents across Wyoming should stay alert to the following common tactics:
| Scam Type | What to Watch For |
|---|---|
| IRS / Tax Scams | Callers claiming you owe back taxes and threatening arrest unless you pay immediately. |
| Utility Shut-off | Fake Rocky Mountain Power reps demanding payment to avoid disconnection in winter. |
| Oilfield / Energy Job Scam | Fake energy or oilfield job offers seeking personal data or upfront “equipment” fees. |
| Farm / Ranch Scam | Fraudulent online listings for cattle, tractors, or ranch equipment aimed at rural buyers. |
If you receive a suspicious call from a 307 number, take these steps to protect yourself:
- Do not share personal information such as Social Security numbers, bank details, or passwords over the phone.
- Hang up and verify by calling the organization back using an official number from its website.
- Report the call to the FTC at reportfraud.ftc.gov and to the Wyoming Attorney General’s Consumer Protection Unit.
- Block the number and consider registering with the National Do Not Call Registry.
Red Flag: Legitimate agencies such as the IRS, Social Security Administration, or your local utility company (Rocky Mountain Power or Black Hills Energy) will never demand immediate payment by gift card, wire transfer, or cryptocurrency. Any 307 caller making such a demand is a scammer.
History and Economy of the 307 Region
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Area code 307 is one of the original 86 codes established in 1947, and because Wyoming is the least populous state, a single code has always been far more than enough. The regional economy is dominated by energy: Wyoming is the largest coal-producing state in the nation, centered on the Powder River Basin around Gillette – often called the “Energy Capital of the Nation” – and is also a major producer of natural gas, oil, uranium, and trona (soda ash). Ranching and cattle remain deeply woven into the state’s culture, Cheyenne anchors state government, the Union Pacific Railroad, F.E. Warren Air Force Base, and the famous Frontier Days rodeo, and tourism is a major force through Yellowstone and Grand Teton national parks, the resort town of Jackson Hole, and Devils Tower. The University of Wyoming is based in Laramie.
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Looking Up a 307 Number
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To identify a 307 caller, use a reverse phone lookup service or search the full 10-digit number online. Many Wyoming businesses, ranchers, and government offices list their 307 numbers publicly, so a quick search often confirms a legitimate caller. For unknown numbers, let the call go to voicemail – genuine callers usually leave a message, while robocallers and scammers rarely do.
Nearby & Related Area Codes
Wyoming is served by the single 307 area code, with no overlay. These neighboring area codes are worth knowing:
You can also browse our full directory of Wyoming area codes for more regional guides.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border Wyoming:
- Montana – area code 406
- Idaho – area code 208
- Utah – area code 801
- Colorado – area code 303
- Nebraska – area code 402
- South Dakota – area code 605
Frequently Asked Questions
Where is the 307 area code located?
The 307 area code covers the entire state of Wyoming, including Cheyenne, Casper, Laramie, Gillette, Rock Springs, Sheridan, Jackson, and Cody.
Does Wyoming have more than one area code?
No. Wyoming is served entirely by the single 307 area code – fitting for the least populous state – with no overlay.
Do I need to dial 10 digits for 307?
As the only area code in Wyoming, 307 has historically allowed 7-digit local dialing, but dialing the full 10 digits is now the recommended standard and always works.
What time zone is the 307 area code in?
The 307 area code observes Mountain Time (MST/MDT), and Wyoming does observe daylight saving time.
Related 307 Guides
- Is a 307 call safe? Read Is area code 307 a scam? Spam & safety guide.
- Local coverage: see the Cheyenne area code guide.
- Worried about spam or robocalls? Browse our Scam Alerts directory.