Alpine Loop — Animas Forks to Engineer Pass via the San Juan High Country
Four passes, three ghost towns, one brutal San Juan circuit.
The Alpine Loop Backcountry Byway is the crown jewel of Colorado’s high-country 4×4 scene — a 65-mile circuit connecting Lake City, Ouray, and Silverton via Engineer Pass (12,800 ft), Cinnamon Pass (12,620 ft), and the ghost town of Animas Forks, a near-complete 1870s silver mining town frozen in place at 11,200 feet. Engineer Pass is the sharper of the two crossings, with loose shelf-road sections on the western descent toward Ouray where the exposure is enough to make a stock Jeep feel narrow. Animas Forks itself sits at the junction and serves as the natural midpoint — the old Duncan house still stands with its bay window overlooking a valley that once held 450 residents through brutal winter conditions.
This is legitimate technical 4×4 terrain. Minimum requirement is a high-clearance 4WD with low-range — lifted rigs with lockers handle it more confidently on the steeper rock sections near Engineer. The loop is typically open early July through mid-September, snow dependent; check with the BLM Lake City Field Office before committing. No permits required. Fuel in Lake City, Ouray, or Silverton — none on the loop itself. Several dispersed campsites exist along the route; the flats near Animas Forks fill up fast on summer weekends. Afternoon thunderstorms are a daily reality in July and August — move off the passes by early afternoon.
Trail Specs
| Difficulty | Difficult |
|---|---|
| Trail Type | Backcountry, Overland Route, Technical 4x4 |
| Surface | Dirt, Gravel, Mixed, Rock |
| Features | Camping, High Altitude, Historic, Remote, Scenic |
| Length (miles) | 65 mi / 104.6 km |
| Duration | 2-3 days |
| Max elevation (ft) | 12800 ft |
| Best season | July-September |
| Minimum vehicle | High-clearance 4WD with low-range |
| Nearest town | Lake City, Colorado |
| Land manager | Bureau of Land Management — Gunnison Field Office |
| Permit required | No |
| Cell service | None |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Official sources | BLM Alpine Loop Byway page BLM Gunnison 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 | |
| Find on Google | Search on Google → |
Location
Trail Conditions
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Frequently asked questions
Can a stock Jeep Wrangler or 4Runner handle the Alpine Loop without modifications?
A stock Wrangler handles it fine. A stock 4Runner with factory skid plates can do it, but tight shelf roads and loose rock sections near Engineer and Cinnamon Passes will test your nerves and your paint. Lift and lockers aren't required, but low-range absolutely is.
When does the Alpine Loop typically open and close each year?
Most years the loop is passable from early July through mid-October, but snow can close passes as late as June and as early as September. Engineer Pass in particular holds snow late — check the BLM Gunnison Field Office for current conditions before you leave pavement.
Do I need a permit or pay any fees to run the Alpine Loop?
No permit and no fee required as of now — it's BLM managed and open to the public. Dispersed camping is free; just follow Leave No Trace and stay out of posted closure areas around the historic mining structures.
What's the hardest section on the loop and what makes it technical?
The descent off Engineer Pass toward Mineral Creek is the crux — steep, loose shelf road with significant exposure and no guardrails. One wrong line on the switchbacks can put your wheels over the edge. Take it slow, hug the mountain, and don't meet someone coming the other way mid-switchback.
Is there any place to resupply fuel or water along the 65-mile loop?
There is no fuel or water resupply on the loop itself — none. Tank up in Lake City or Ouray before you start, and carry at least 2 gallons of water per person. At 12,000+ feet, altitude hammers your body faster than you expect.
Trail track
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