Bighorn Mountains

State: Wyoming, extending into southern Montana. Type: mountain range and national forest (Bighorn National Forest, 1,120,000 acres). Highest peak: Cloud Peak, 13,171 feet; second-highest: Black Tooth Mountain, 13,009 feet. Contains the roughly 189,000-acre Cloud Peak Wilderness. Formed during the Laramide orogeny about 70 million years ago; Precambrian rock as old as 3.25 billion years is exposed.

The Bighorn Mountains rise abruptly from the Great Plains in north-central Wyoming, extending about 200 miles north into southern Montana and separated from the Absaroka Range by the Bighorn Basin. Uplifted roughly 70 million years ago during the Laramide orogeny, the range exposes more than 9,000 feet of sedimentary rock spanning the Cambrian through Lower Cretaceous periods, along with some of the oldest Precambrian rock on Earth, dated to 3.25 billion years. Cloud Peak, the range's highest point at 13,171 feet, anchors the Cloud Peak Wilderness within the surrounding Bighorn National Forest, a 1,120,000-acre forest that also holds the highest peaks in Wyoming outside the Tetons. Because the mountains capture far more moisture than the arid plains around them, they function as a highland oasis feeding the headwaters of the Little Bighorn, Tongue, and Powder rivers, and support hiking, fly fishing, hunting, and increasingly ATVing and snowmobiling.

The Bighorn Mountains lie in north-central Wyoming, running north into southern Montana, bordered on the west by the Bighorn Basin and the Absaroka Range. The Bighorn National Forest Supervisor's Office is located at 95 Highway 16/20, Greybull, WY 82426.

Elevation drives heavy annual snowfall in the Bighorns, creating conditions markedly wetter than the surrounding arid plains and earning the range a description as a highland moisture oasis. Specific temperature and precipitation figures were not confirmed from the sources reviewed.

Summer is generally the main season for hiking and the Cloud Peak Wilderness, given the range's high elevation and heavy snowpack; winter brings snowmobiling and other snow-based recreation. Specific month-by-month guidance was not detailed in the sources reviewed.

The Bighorn Mountains were uplifted approximately 70 million years ago during the Laramide orogeny, the same mountain-building episode responsible for much of the modern Rocky Mountain front. The range's rock record spans over 9,000 feet of sedimentary strata from the Cambrian through Lower Cretaceous periods, with Precambrian basement rock dated to as old as 3.25 billion years, among the oldest exposed rock in the world.

Popular activities include hiking and backpacking (notably in the Cloud Peak Wilderness), fly fishing, hunting, and, increasingly, ATVing and snowmobiling. The range hosts the Bighorn Trail Run, a 100-mile ultramarathon described as one of the elite ultra-distance races in the country, along with over 1,200 miles of trail across the national forest.

Cloud Peak (13,171 feet) and Black Tooth Mountain (13,009 feet) are the range's signature summits, both within or near the Cloud Peak Wilderness, a roughly 189,000-acre roadless area. The wider Bighorn National Forest encompasses the highest peaks in Wyoming outside Yellowstone/Grand Teton country and provides the headwaters for the Little Bighorn, Tongue, and Powder rivers.

The Bighorn National Forest Supervisor's Office is in Greybull, Wyoming; the range is accessed by highway from surrounding towns in north-central Wyoming. Specific driving routes and nearest-airport details were not confirmed from the sources reviewed.

As a national forest and mountain range, the Bighorns have no single set of opening hours; the Forest Supervisor's Office keeps standard business hours of Monday-Friday, 8:00 a.m. to 4:30 p.m., closed on federal holidays. Individual trailheads and campgrounds may have seasonal access windows tied to snowpack.

General access to Bighorn National Forest is free; developed recreation sites charge their own fees, with single campsites around $20 per night and group sites starting at about $99 per night for 1-35 people, per Forest Service information. Some sites, such as interpretive areas, have no fee.

A day trip can cover scenic drives and shorter trails, but multi-day backpacking is common for those exploring the Cloud Peak Wilderness or attempting Cloud Peak itself.

Camping is available at developed Forest Service campgrounds throughout the national forest; surrounding towns in north-central Wyoming (near Greybull and along the range's edges) provide additional lodging options, though specific hotel names were not confirmed from the sources reviewed.

Dining is concentrated in the towns surrounding the range rather than within the forest itself; specific restaurants were not confirmed from the sources reviewed.

The Bighorn Basin lies to the west, separating the range from the Absaroka Range; the Little Bighorn, Tongue, and Powder river valleys, which originate in the Bighorns, connect the range to the surrounding plains communities.

The Bighorn National Forest Supervisor's Office in Greybull, Wyoming, is a central administrative point; specific nearest-airport and public-transit information was not confirmed from the sources reviewed, so a personal or rental vehicle is the practical way to reach trailheads.

High-elevation weather can change quickly, and heavy snowpack affects access for much of the year, so check current conditions before hiking or driving into the backcountry. Standard wilderness precautions apply in the roadless Cloud Peak Wilderness, where cell service and rescue access are limited.

Layered clothing for rapid weather changes at altitude, sufficient water and navigation tools for backcountry travel, and standard camping or hiking gear appropriate to season.

Reserve developed campsites in advance during busy summer months, and check seasonal road/trail status before heading into the Cloud Peak Wilderness or higher elevations, since snowpack can restrict access outside summer.

Dial 911 for any emergency. For general forest information, contact the Bighorn National Forest Supervisor's Office at (307) 548-5304 or SM.FS.bighorninfo@usda.gov.

Bighorn National Forest (U.S. Forest Service) - https://www.fs.usda.gov/bighorn

This section is being updated and will be available shortly.

This section is being updated and will be available shortly.

This section is being updated and will be available shortly.