Lonesome Highway — Centennial Road to Tensleep Canyon via Shell Creek Road and Medicine Lodge
10,000 years of history, zero crowds.
This loop drops off the Bighorn Mountains’ west face via Shell Creek Road (County Road 30), a narrow clay-and-gravel track that turns treacherous when wet, then cuts south across the basin floor to Medicine Lodge State Archaeological Site near Hyattville — one of Wyoming’s most significant rock art panels, with 10,000 years of petroglyphs carved into a 750-foot sandstone wall above a perennial creek. From there the route connects back north through Alkali Creek Road and the ochre badland benches above the Greybull River. The shelf sections on Shell Creek Road require careful wheel placement, especially the descent into the creek bottom where the road narrows to one lane with a steep cut bank on the uphill side.
High-clearance 4WD is the minimum — don’t attempt Shell Creek Road in a wet year without checking conditions at the Greybull BLM office first. The clay surface turns to axle-deep grease after rain. Best run June through September. Greybull is your last fuel stop heading east; shell out for a full tank before leaving pavement. No permit required for the state archaeological site day use, but camping is available at the site’s primitive campground for a small fee. Cell service is spotty in the basin and nonexistent on the shelf road sections. Bring your own water.
Trail Specs
| Difficulty | Moderate |
|---|---|
| Trail Type | Backcountry, High Clearance, Overland Route |
| Surface | Dirt, Gravel, Mixed |
| Features | Camping, Historic, Remote, Scenic |
| Length (miles) | 58 mi / 93.3 km |
| Duration | 1-2 days |
| Max elevation (ft) | 6800 ft |
| Best season | June-September |
| Minimum vehicle | High-clearance 4WD |
| Nearest town | Greybull, WY |
| Land manager | BLM Cody Field Office / Wyoming State Parks |
| Permit required | No |
| Cell service | Spotty |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Official sources | Medicine Lodge State Archaeological Site BLM Cody Field Office |
| Start coordinates | |
| End coordinates | |
| Copy both for Google Maps directionsClick to copy the directions URL · or open it directly in a new tab | |
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Location
Trail Conditions
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Frequently asked questions
Can a stock Tacoma or 4Runner run this trail, or do I need a lift?
A stock high-clearance 4WD handles it fine. Lifted rigs have more margin on the rougher sections near Shell Creek, but factory skids and all-terrain tires are sufficient for most conditions.
When does this route typically open after winter, and is snow a real risk in June?
June through September is the reliable window. Snow can linger into late May at the higher elevations, and fall storms hit early — late September can turn the dirt sections greasy fast.
Do I need a permit to camp at Medicine Lodge State Archaeological Site?
Camping at the state archaeological site requires a Wyoming State Parks day-use or camping fee. Dispersed camping on the BLM sections along Shell Creek Road is free with no permit required.
What's the hardest section, and what should I actually expect?
The roughest stretch is along Shell Creek Road where the two-track tightens and shelf road exposure increases before dropping into the canyon. Nothing technically extreme, but loose gravel, off-camber corners, and no guardrails keep you honest.
How far is the nearest gas from the route, and is cell service reliable enough to skip a satellite communicator?
Greybull is your last reliable fuel stop before the run — top off there. Cell service is spotty to nonexistent for most of the 58 miles, so a satellite communicator isn't optional out here, it's just smart.
Trail track
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