307 Area Code: The Single Number That Means Wyoming

The 307 area code covers the entire state of Wyoming — every city, town, ranch, and national park, from the capital at Cheyenne to Casper, Laramie, Gillette, and the mountain resort town of Jackson.

It is one of the original 1947 area codes, and to this day Wyoming remains one of the very few states served by a single area code. For locals, "307" is more than a dialing prefix — it is a point of pride and a shorthand for the state itself.

This guide explains where 307 reaches, why Wyoming has never needed a second code, what the state's economy runs on, how to dial correctly, how to avoid 307 scams, and how to get a 307 number for your business from anywhere.

Where is the 307 area code?

The 307 area code serves all of Wyoming — roughly 98,000 square miles across all 23 counties, making it one of the largest single-code areas by land in the country. From Cheyenne on the Colorado border to Yellowstone in the northwest, every landline, cell, and VoIP number in the state begins with 307.

Cities and communities inside the 307 footprint include:

Neighboring states use their own codes — Colorado uses 303 and 970, Montana uses 406, Utah uses 435, Idaho uses 208, and Nebraska uses 308.

Why Wyoming has just one area code

When the North American Numbering Plan launched in 1947, Wyoming was assigned 307 — and unlike almost every other state, it has never needed a second one. The reason is simple: Wyoming is the least-populous state in the country, with roughly 580,000 residents spread across a vast landscape.

A single area code holds about 7.9 million possible numbers, far more than Wyoming's population and businesses have ever come close to exhausting. That puts 307 in rare company. Only a handful of states still run on one code; Maine, for example, has used its 207 area code statewide since 1947 and has never split or added an overlay either. Barring explosive growth, Wyoming is expected to keep 307 as its sole code for the foreseeable future — there is no overlay planned.

What the 307 region runs on

Wyoming's economy is small in headcount but outsized in output, anchored by land, energy, and tourism. Understanding that mix explains who actually uses 307 numbers:

• Energy — Wyoming is the nation's top coal producer and a major source of natural gas, oil, and uranium. The Powder River Basin around Gillette and the oil fields around Casper drive much of the state's business activity.
• Tourism — Yellowstone and Grand Teton National Parks, plus Jackson Hole's resort economy, draw millions of visitors a year and support hospitality, outfitting, and real-estate businesses statewide.
• Ranching and agriculture — cattle ranching remains central to Wyoming's identity and rural economy.
• Business-friendly policy — Wyoming levies no state income tax and has become a popular state for company formation and LLC registration, which means many 307-registered businesses operate far beyond the state's borders.

A 307 number signals membership in this statewide community — useful for energy services, tourism operators, ranching suppliers, real-estate teams, and any business serving customers across the Cowboy State. You can get a local 307 number from My Country Mobile to reach them.

How to dial a 307 number

Because Wyoming has no overlay, seven-digit local dialing technically still works inside the state — but the safe modern habit, and the standard for businesses, is to always dial the full ten-digit number.

The 307 area code sits in the Mountain Time Zone (MT) — MST (UTC−7) in winter and MDT (UTC−6) in summer, the same clock as Denver and Salt Lake City. At noon in Cheyenne it is 2 PM in New York, 1 PM in Chicago, and 11 AM in Los Angeles.

307 area code scams

Even a tight-knit statewide code gets abused. Fraudsters spoof 307 numbers — faking a Wyoming prefix, sometimes matching the first digits of your own number — so a call looks local and trustworthy. A 307 on your screen does not prove the caller is really in the state.

A few habits keep you safe:

• Let unknown 307 calls go to voicemail; legitimate callers leave a message.
• Never share one-time codes, card numbers, or login details with an inbound caller.
• Be skeptical of "utility shutoff," "Social Security suspended," or "your account is compromised" calls that pressure you to act fast.
• Use carrier spam filtering. The FCC's STIR/SHAKEN call authentication framework is why many phones now label these calls as "Spam Risk."

Why a 307 number carries weight

In a state where everyone recognizes the code, a 307 number is instant local credibility. A Cheyenne contractor, a Jackson outfitter, or a Casper energy-services firm reads as "one of us" when the caller ID shows 307 — and local numbers earn higher answer rates than unfamiliar out-of-state or toll-free lines.

That trust is practical and commercial. For a business courting Wyoming customers — or an out-of-state company that has registered an LLC in the state and wants a matching local presence — a 307 number is both a signal of belonging and a measurable lift in pickups.

Getting a 307 number for your business

If you serve Wyoming — energy, tourism, ranching supply, trades, or professional services — a 307 number puts a Cowboy State address on your caller ID without an in-state lease. It signals you are plugged into the local market and lifts answer rates with Wyoming contacts.

You do not need a Cheyenne office to claim one. A cloud phone provider can assign you a 307 number that rings on your existing devices and routes calls anywhere in the world. With a provider like My Country Mobile, you can pick a 307 line, configure routing, an auto-attendant, and voicemail, and be live in minutes — whether you are a one-person shop or a national brand opening a Wyoming presence.

Key takeaways

• 307 covers all of Wyoming — all 23 counties, every city and town.
• It has been the state's only area code since 1947, with no split or overlay ever added.
• As the least-populous state, Wyoming is unlikely ever to need a second code.
• The region sits in Mountain Time.
• You can get a 307 number from the cloud without a Wyoming address.

Frequently asked questions