How difficult is Alpine Loop – Colorado Overland Route?

Alpine Loop – Colorado Overland Route is rated hard. The route runs 65 miles.

What kind of vehicle do you need for Alpine Loop – Colorado Overland Route?

About two-thirds of the route is passable in 2WD on graded gravel. The complete loop, including Engineer Pass (12,800 ft) and Cinnamon Pass (12,640 ft), requires a high-clearance 4WD with low range and recovery gear.

When is the best time to drive Alpine Loop – Colorado Overland Route?

The best months are Jul, Aug, Sep. Avoid Nov, Dec, Jan, Feb, Mar, Apr.

Is there cell service on Alpine Loop – Colorado Overland Route?

Limited near Lake City, Silverton, and Ouray; absent through most of the loop and at the passes.

Alpine Loop – Colorado Overland Route

Last verified May 2026

The Alpine Loop Backway is a 65-mile mountain loop in the San Juan Mountains of southwestern Colorado, connecting the historic mining towns of Lake City, Silverton, and Ouray. The route is designated a Bureau of Land Management Backcountry Byway and crosses lands managed by both BLM and San Juan National Forest. Two high passes — Engineer Pass at 12,800 feet and Cinnamon Pass at 12,640 feet — make it one of the highest sustained 4WD routes in the lower 48.

About two-thirds of the loop is passable in a standard 2WD vehicle on graded gravel. The pass connections require a high-clearance 4WD with low range. The upper passes typically open in May or early June and close in late October; lower-elevation segments open earlier in spring and stay open longer in fall.

Trailhead: 37.80487, -107.66965

Technical Difficulty: hard
Length: 65 miles
Direction: Loop
Vehicle: About two-thirds of the route is passable in 2WD on graded gravel. The complete loop, including Engineer Pass (12,800 ft) and Cinnamon Pass (12,640 ft), requires a high-clearance 4WD with low range and recovery gear.
Nearest town: Lake City, Colorado
Terrain: 65 miles of mountain backroads through the San Juans — graded gravel at lower elevations, rocky shelf road and tight switchbacks above 11,000 feet, with two passes over 12,500 feet.
Cell coverage: Limited near Lake City, Silverton, and Ouray; absent through most of the loop and at the passes.
Best months: Jul, Aug, Sep
Management: San Juan National Forest, Bureau of Land Management
Trailhead: 37.80487, -107.66965

Resources

Plan in Epic Plans Official site Open in Google Maps

Maps

Brochures & guides

Useful links

Directions

From Lake City, take County Road 30 (Cinnamon Pass Road) west off CO-149 just south of town to begin the loop. The route can also be entered from Silverton via County Road 2 (Cinnamon Pass) or from Ouray via County Road 18 (Engineer Pass). Choose the entry that matches your direction of travel and current pass conditions.

Approximate Lake City coordinates: 37.989° N, -107.314° W.

Photos · 10

Getting Oriented

The Alpine Loop sits in the San Juan Mountains of southwestern Colorado and connects Lake City, Silverton, and Ouray. The route is designated as a BLM Backcountry Byway and crosses lands managed by both the Bureau of Land Management and San Juan National Forest. Lake City (population ~430) is the most common starting point and the only town on the eastern side of the range. Silverton and Ouray, both former silver-mining boomtowns, sit on the western side and host the Million Dollar Highway between them. Elevation along the loop ranges from roughly 8,700 feet at Lake City to 12,800 feet at Engineer Pass.

Trail Overview

Access is possible from three primary entry points: Lake City via County Road 30 or County Road 20, Silverton via County Road 2, and Ouray via County Road 18. From Lake City, the standard counterclockwise direction climbs Cinnamon Pass first to Animas Forks, then either descends to Silverton or continues over Engineer Pass to Ouray. The lower segments are graded gravel passable in 2WD; the upper passes are rocky shelf road with steep grades and tight switchbacks that require high-clearance 4WD with low range. Allow a full day for the complete loop without side trips. Signage at the trailheads marks the byway, but cell service is limited to nonexistent above the towns, so download or print maps in advance.

Points of Interest

Engineer Pass. 12,800 feet. The highest pass on the route, with panoramic views of the Uncompahgre Wilderness. The east-side ascent is rocky and exposed.
Cinnamon Pass. 12,640 feet. Wildflower meadows on the approach and a steep descent into Animas Forks. Less technical than Engineer but still 4WD-only at the top.
Animas Forks. Ghost town at the confluence of the loop's two passes. Well-preserved structures and interpretive signage.
Capitol City. Smaller ghost town on the Lake City side, with the remains of an 1870s smelter.
Lake San Cristobal. The second-largest natural lake in Colorado, just south of Lake City.
Million Dollar Highway. US-550 between Silverton and Ouray, paved but dramatic, often combined with the loop.
Alpine tundra and wildlife. Marmots, pika, elk, and occasional black bear in the higher meadows.

Where to Camp

Dispersed camping is allowed on the National Forest portions of the route; check the San Juan NF motor vehicle use map for closures. Developed options:

Lake San Cristobal area. Several USFS campgrounds south of Lake City with lake views.
Animas Forks area. Dispersed sites near the ghost town.
Silverton and Ouray. Both towns have private campgrounds, cabins, and lodging.

Tips for a Safe and Enjoyable Trip

Check the San Juan National Forest roads status page for current pass conditions before going.
Carry chains or traction boards even in summer — afternoon storms can drop snow at the passes any month of the year.
Download offline maps; cell service drops out above the towns.
Top off fuel in Lake City, Silverton, or Ouray. There is no fuel on the loop itself.
Yield to uphill traffic on the shelf sections — the road is one-lane in places, and passing requires backing to a wider spot.
Carry recovery gear, a full-size spare, and warm layers regardless of the forecast.
Stay on the established route; alpine tundra is fragile and slow to recover.

Common questions

How difficult is Alpine Loop – Colorado Overland Route?: Alpine Loop – Colorado Overland Route is rated hard. The route runs 65 miles.
What kind of vehicle do you need for Alpine Loop – Colorado Overland Route?: About two-thirds of the route is passable in 2WD on graded gravel. The complete loop, including Engineer Pass (12,800 ft) and Cinnamon Pass (12,640 ft), requires a high-clearance 4WD with low range and recovery gear.
When is the best time to drive Alpine Loop – Colorado Overland Route?: The best months are Jul, Aug, Sep. Avoid Nov, Dec, Jan, Feb, Mar, Apr.
Is there cell service on Alpine Loop – Colorado Overland Route?: Limited near Lake City, Silverton, and Ouray; absent through most of the loop and at the passes.

Hazards

Altitude. Passes top out near 12,800 feet. Acclimatize before tackling the loop if coming from sea level.
Afternoon thunderstorms. Common in summer, with lightning above treeline. Plan to be off the passes by early afternoon.
Narrow shelf road. Sections of Engineer Pass are one-lane with no guardrail; passing requires backing to a wider spot.
Loose rock and washouts. The 4WD segments include steep loose climbs and stretches eroded by spring runoff.
Snow any month. The upper passes can hold snow into July and pick up new snow by September.
Limited cell coverage. Carry a satellite messenger for the technical sections.