Area Code 307
Wyoming
Area code 307 serves Wyoming, primarily Cheyenne, in the Mountain Time (MT) time zone. It has served the region since 01-Jan-1947.
Historical Timeline of Area Code 307
Area code 307 was created in 1947 as one of the original 86 North American area codes by AT&T under the North American Numbering Plan. It has never undergone an overlay or split, making it one of the longest-running single area codes in North America. Wyoming's sparse population kept telephone demand low, with under 400,000 landlines in 1995 growing to over 800,000 assigned numbers by 2011. NANPA projects 307 will remain Wyoming's sole area code until at least 2040. Source: Wikipedia
Key milestones:
- 1947: Created as one of the original 86 North American area codes by AT&T under the North American Numbering Plan. Source: Wikipedia
- 1995: Wyoming had under 400,000 telephones, mostly landlines, according to former Qwest executive Mike Ceballos. Source: Cowboy State Daily
- 2011: Over 800,000 telephone numbers assigned in Wyoming. Landline numbers declining while wireless grows. Source: Cowboy State Daily
- 2021: FCC confirmed NANPA projects Wyoming will not need a second area code until 2045, when current 307 numbers will be exhausted. Source: Cowboy State Daily
- 2025: NANPA data management lead Heidi Wayman confirmed 307 is safe for at least 20 more years. Wyoming remains one of 11 states with a single area code. Source: Cowboy State Daily
Area code 307 has maintained its original boundaries since 1947, covering the entire state of Wyoming. This stability reflects the state's low population density and gradual telephone number consumption over 78 years.
Unique Facts About Area Code 307
Area code 307 has several characteristics within the North American Numbering Plan. As one of the original 86 area codes created in 1947, it has never been split or overlaid, making it one of the longest-running single area codes in North America. The code covers the entire state of Wyoming, and its longevity reflects the state's low population density and gradual telephone number consumption. Source: Wikipedia
- No overlay or split since 1947: Area code 307 has never undergone an overlay or split since its creation in 1947. It has maintained its original boundaries for over 78 years, covering the entire state of Wyoming. Source: Wikipedia
- Exhaustion projected 2040-2045: NANPA projects Wyoming's 307 numbers will be exhausted around 2040-2045. When a new area code is eventually needed, it will be an overlay covering the entire state, not a geographic split. Source: Cowboy State Daily
- 920+ businesses use 307 as brand identity: Over 920 businesses in Wyoming register with names starting with '307,' including 307 Vodka, 307 Made, and 307 Productions. The code represents the West and the cowboy identity of the Cowboy State. Source: Cowboy State Daily
- One of 11 states with a single area code: As of May 2025, Wyoming is one of 11 states served by a single area code. The others are Alaska, Delaware, Hawaii, Maine, Montana, New Hampshire, North Dakota, Rhode Island, South Dakota, and Vermont. Source: Wikipedia
- 7-digit local dialing still supported: Area code 307 supports 7-digit local dialing because it has no overlay. This avoids 988-XXXX number conflicts that have affected other area codes. Source: Cowboy State Daily
These characteristics reflect Wyoming's position in the North American Numbering Plan, where low population density has allowed a single area code to serve the entire state since 1947.
FCC Regulatory History
Area code 307 has not required any FCC regulatory action since its establishment in 1947. No overlays, splits, or relief proceedings have been initiated for this code. NANPA projects exhaustion around 2040-2045, which would trigger future relief proceedings, but no formal dockets currently exist. Source: Cowboy State Daily
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 1947 | NANP established | AT&T Nationwide Numbering Plan | AT&T establishes the North American Numbering Plan, assigning 307 to Wyoming. The state is designated as a single-NPA state, meaning one area code covers the entire state. Source: Wikipedia |
| 2021 | FCC exhaustion projection | NANPA projection | FCC spokeswoman Anne Veigle confirmed NANPA projects Wyoming will not need a second area code until 2045, when current 307 numbers will be exhausted. No relief proceeding has been initiated. Source: Cowboy State Daily |
| 2025 | NANPA confirmation | NANPA data review | NANPA data management lead Heidi Wayman confirmed 307 is safe for at least 20 more years. No relief action is anticipated before 2040. Source: Cowboy State Daily |
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 307).
| County | Population | Share |
|---|---|---|
| Laramie, WY | 101,225 | 14.7% |
| Natrona, WY | 80,403 | 11.7% |
| Campbell, WY | 52,573 | 7.6% |
| Sweetwater, WY | 50,053 | 7.3% |
| Albany, WY | 44,598 | 6.5% |
| Fremont, WY | 39,468 | 5.7% |
| Sheridan, WY | 31,854 | 4.6% |
| Park, WY | 31,271 | 4.5% |
| Big Horn, WY | 30,884 | 4.5% |
| Big Horn, MT | 25,727 | 3.7% |
| Teton, WY | 23,942 | 3.5% |
| Lincoln, WY | 19,921 | 2.9% |
| Converse, WY | 17,621 | 2.6% |
| Niobrara, WY | 17,296 | 2.5% |
| Carbon, WY | 15,005 | 2.2% |
| Goshen, WY | 14,665 | 2.1% |
| Hot Springs, WY | 11,655 | 1.7% |
| Crook, WY | 10,313 | 1.5% |
| Johnson, WY | 10,084 | 1.5% |
| Weston, WY | 9,232 | 1.3% |
| Sublette, WY | 8,806 | 1.3% |
| Platte, WY | 8,723 | 1.3% |
| Washakie, WY | 7,836 | 1.1% |
| Uinta, WY | 5,806 | 0.8% |
| Custer, SD | 5,411 | 0.8% |
| Pennington, SD | 5,411 | 0.8% |
| Caribou, ID | 3,726 | 0.5% |
| Weld, CO | 1,675 | 0.2% |
| Banner, NE | 1,675 | 0.2% |
| Kimball, NE | 1,675 | 0.2% |
Call Context
This area code covers multiple cities and communities across a broad region in Wyoming. It is one of the original area codes established when the North American Numbering Plan was created in 1947.
Nearby Area Codes
Area codes geographically closest to 307.
Frequently Asked Questions
Common questions about area code 307 and how phone numbering works.
Phone numbers are assigned based on where the number was originally provisioned, not the caller's current location. Mobile phones retain their number when users move, and businesses may use numbers from regions where they don't have a physical presence. VoIP services can also provision numbers from virtually any area code.
Yes, mobile phones can have numbers from any area code in the region they were activated. Wireless carriers assign numbers from available pools regardless of phone type. When users change carriers or move to new areas, they typically keep their original number, which may have a different area code than their current location.
Start by looking up the area code on this site to understand its general geographic region. For the specific number, options include using your carrier's caller ID features or checking public directories. If you suspect fraud, you can report it to the FTC. To file a complaint about robocalls or spoofed numbers, visit the FCC Consumer Complaint Center. You can also register your number with the National Do Not Call Registry to reduce unwanted calls. Keep in mind that caller ID can display any name the caller chooses to set.
While Arlington is a prominent city in this area code's coverage, the code serves the broader surrounding region as well. Area codes are assigned geographically and typically cover multiple cities, towns, and communities beyond any single anchor city.
Yes, this is one of the original area codes established in 1947 when the North American Numbering Plan (NANP) was created. The initial set of area codes was designed to cover all of North America with a unified dialing system, and many of these original codes remain in use today, though some have been split or received overlays.
The estimated total population served by area code 307 is based on aggregated U.S. Census Bureau data for the counties within this area code. The population varies significantly between dense urban codes serving millions and rural codes covering smaller populations. You can find the specific population figure in the demographics section above.