Lonesome Highway — Bighorn Mountains Powder River Country to Ten Sleep via the West Slope Bench
Wyoming's forgotten west slope, limestone and sage.
US-16 over Powder River Pass is the postcard. This isn’t that road. The west slope bench track runs parallel and below the main pass, starting near the Hazelton Road junction on the eastern Bighorn foothills and cutting across wide sage benches above Tensleep Creek before dropping into the lower reaches of Ten Sleep Canyon via a series of tight limestone shelves. You pass abandoned homestead foundations, cross Tensleep Creek twice at cobblestone fords, and come out at the canyon floor with Bighorn National Forest above you and the Bighorn Basin floor stretching west into nothing. The geology shifts every few miles — red Chugwater sandstone, white Madison limestone, grey Tensleep sandstone — a stratigraphic road cut with no guardrails and no crowds.
The route is rated moderate to difficult depending on water levels at the creek fords. In spring runoff the crossings get thigh-deep; by August they’re ankle-deep cobble. A high-clearance 4WD handles it dry; lockers are useful on the slick limestone shelf sections. No permit required. Dispersed camping is available throughout the Bighorn National Forest sections. Fuel and water in Ten Sleep or Worland before you head up. Best season is June through September. Cell service is nonexistent above the canyon rim.
Trail Specs
| Difficulty | Moderate |
|---|---|
| Trail Type | High Clearance, Overland Route |
| Surface | Dirt, Gravel, Mixed, Rock |
| Features | Camping, Historic, Remote, Scenic, Water Crossings |
| Length (miles) | 34 mi / 54.7 km |
| Duration | 1-2 days |
| Max elevation (ft) | 8640 ft |
| Best season | June-September |
| Minimum vehicle | Stock 4WD high-clearance |
| Nearest town | Ten Sleep, WY |
| Land manager | Bighorn National Forest |
| Permit required | No |
| Cell service | None |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Official sources | Bighorn National Forest |
| Start coordinates | |
| End coordinates | |
| Copy both for Google Maps directionsClick to copy the directions URL · or open it directly in a new tab | |
| Find on Google | Search on Google → |
Location
Trail Conditions
No recent condition reports. Be the first to post one.
Log in to post a condition report.
Frequently asked questions
Can a stock 4Runner or Wrangler handle this trail without any lift?
Yes. A stock 4WD high-clearance rig is the minimum and will get through under normal conditions. The mixed rock and rutted dirt sections don't require extra lift, but low-range traction is non-negotiable on the steeper bench descents.
When does this route typically open in spring and is it passable in early October?
June through September is the reliable window. Spring snowmelt turns the bench roads into grease, and the high sections near 8,600 ft can see snow again by late September or early October. Don't count on it before Memorial Day.
Do I need a permit to run this route or camp out here?
No permit required. The route falls under Bighorn National Forest jurisdiction, and dispersed camping is allowed under standard National Forest rules — 14-day stay limit, 200 feet from water sources and roads. No fees.
What's the hardest section and what makes it technical?
The steepest challenge is the descent off the west slope bench toward Ten Sleep, where loose rock and eroded limestone shelf road narrow up and drop away. It's not extreme, but it's unforgiving if you're moving too fast or conditions are wet — take it slow and pick your line.
Are the water crossings actually deep enough to matter, and where do I find water for camp?
The crossings are seasonal and typically shallow in summer — most rigs splash through without drama, but early June runoff can change that fast. Natural water sources exist along the route but treat everything; there's no developed water and zero cell service to call for help if something goes wrong.
Trail track
No GPX track for this trail yet. If you've driven it and have a track, contribute below.
Log in to contribute a GPX track.