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.
Demographics & Economics
- Total Population
- 688,534
- Population Density
- 5 people/sq mibelow U.S. average (U.S.: 93 people/sq mi)
- Median Household Income
- $71,247near U.S. median (U.S.: $75,144)
- Poverty Rate
- 11.6%near U.S. average (U.S.: 11.5%)
- Unemployment Rate
- 4.1%above U.S. average (U.S.: 3.6%)
- Education Attainment
- Bachelor's Degree+29.3%below U.S. average (U.S.: 33.7%)High School or Lower29.9%
Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.
See how this area code compares to all US area codes in the Statistics dashboard.
Time Zone
- Mountain Time (MT)
NANPA Relief Status
According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.
Source: NANPA NPA Relief Planning Reports · See all relief planning statuses
Current Time
Prefix Utilization
Geographic Coverage
State
WY
Major Cities
- Cheyenne
- Casper
- Gillette
- Laramie
- Rock Springs
- Sheridan
- Evanston
- Green River
- Riverton
- Jackson
- Cody
- Rawlins
- Lander
- Powell
- Douglas
- Ranchettes
- Torrington
- Worland
- South Greeley
- Buffalo
- Mills
- Fox Farm-College
- Wheatland
- Newcastle
and 180 more cities
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.
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% |
Area Code 307 Family Tree
Area code 307 is an original area code with no splits or overlays. It has been in service since 01-Jan-1947.
Call Context
This area code covers a primarily rural region in WY with low population density. The largest community is Cheyenne.
Nearby Area Codes
Area codes geographically closest to 307.
