307 area code
Cheyenne area, Mountain Time.Area code 307 covers Cheyenne, Casper, Gillette and 89 more places in Wyoming, on Mountain Time.
Right now in Cheyenne
Mountain Time (MST, UTC-7; MDT, UTC-6 in summer)
Calling hours: Every day, 8 AM to 8 PM (Wyoming law)
Small talk
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Where 307 numbers come from
Numbers are issued by rate center, a billing area named for its main town. 307 has 92. Each one's share is how many 307 numbers start there.
- Cheyenne12%
- Casper8%
- Gillette4%
- Jackson4%
- Laramie4%
- Rock Springs3%
- Sheridan3%
- Cody3%
- Evanston3%
- Riverton3%
- Lander2%
- Green River2%
Also: Powell, Buffalo, Douglas, Rawlins, Afton, Wheatland, Pinedale, Torrington, Kemmerer, Lusk, Newcastle, Sundance + 68 more
Share of exchanges (blocks of 10,000 numbers). Source: NANPA rate center and exchange reports, November 10, 2026
When can you call a 307 number?
Sales calls to homes and cell phones have legal hours, set by Wyoming law. Hold every 307 number to them, since you can't tell a work line from a personal cell.
What applies to 307Every day, 8 AM to 8 PM
- Federal (TCPA and FTC rule)Every day, 8 AM to 9 PMCalls to residential and mobile numbers. Most calls to businesses are exempt from the FTC's rule.47 CFR 64.1200(c)(1); 16 CFR 310.4(c) (opens in a new tab)
- Wyoming lawEvery day, 8 AM to 8 PMWyo. Stat. 40-12-302(d) (opens in a new tab)
Local time comes from the area code, not from where the person is today. Mobiles keep their number when they move. Calling hours here are a guide, not legal advice. Every state's calling hours, with sources
The 307 area code
307 is one of the original area codes from 1947. Local calls can still be dialed with 7 digits.
- 1947307 starts
Source: NANPA area code database
Calling a list of 307 numbers?
Paste it into the free phone number validator. It checks every number, finds each one's time zone and sorts the list by who you can call right now.
307 area code FAQ
What area code is 307?
307 is a Wyoming area code for Cheyenne, Casper, Gillette, Jackson and 88 more places.
What time zone is the 307 area code in?
Mountain Time (MST, UTC-7; MDT, UTC-6 in summer).
What are the calling hours for 307 numbers?
Every day, 8 AM to 8 PM, local time, under Wyoming law.
When did the 307 area code start?
In 1947: it's one of the original area codes.
Calling 307 numbers? Reach more of them.
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