Mosquito Pass

4.7/5 (105 reviews)
Leadville, Colorado (Lake County)
Last Updated: 12/18/2022

Trail Information


Mosquito Pass (elevation 13,185'), between Alma and Leadville, Colorado, is among the highest Colorado passes accessible to 4WD vehicles. The views from here are spectacular, especially in early autumn when the valley’s foliage begins to change color. The vibrant gold, amber, and green colors provide a stark contrast to the drab brown stone and paled grasses covering the high treeless ridges. Earlier in the summer, the alpine grasses and wildflowers are spectacular. However, check with the Forest Service District Offices because Mosquito Pass opens late due to snow blocking the road. Pike National Forest/South Park Ranger District (719) 836-2031 San Isabel National Forest/Leadville Ranger District (719) 486-0749

Trail Difficulty and Assessment

Trail Navigation

Mosquito Pass is a very rocky road. From east or west, the lower portions are mostly dirt and gravel. As you gain elevation, the rocks become larger (6" to 8" diameter). Several segments of the road are entirely covered in loose stones up to 10" diameter, giving the sensation of driving on bowling balls. At the highest elevations, there are numerous switchbacks, but all are sufficiently wide so as not to require three-point turns. At these locations, trail surface is exposed bedrock. Mosquito Pass also includes a few shelf road portions that preclude passing.

Trail Reviews

4.7/5 (105)
Seasonal Closure
Visited: 10/07/2022

The pass is now closed for the season
Rated 5/5
Visited: 09/27/2022
Difficulty Accuracy: Spot On

Went from the Alma-side to Leadville. Waypoint 5 to 6 is not bad if you choose the right lines. Between 7 and 8 there is a nice tricky spot where I was balancing on two wheels. Between 10 and 11 there are some switchbacks that are very angled, take your time in your approach as these can be tricky to maneuver downhill. Once I reached the top it was flurrying. Some other mountain tops nearby had a bit of snow on them. Vehicle: 4Runner with skid plates, still waiting on suspension upgrades, so at the moment I probably having less clearance than stock.
Rated 5/5
Visited: 09/23/2022
Difficulty Accuracy: Spot On

Rocky trail as previous review says and mud puddles are pretty deep for low clearance stock vehicles. Good run to Leadville with nice views
Rated 5/5
Visited: 09/17/2022
Difficulty Accuracy: Spot On

Took a stock Tacoma with ATs, a stock Tundra with ATs, 2 stock 4Runners with ATs. They scraped a little bit, but nothing serious - just small polishing of their engine skid plates. Trail is rocky/bumpy. Those without lifts and bigger tires will need to take their time, but this trail is by no means difficult. Ran it with my 4Runner with a lift and 285s ATs and another 4Runner with a very similar build. No scraping, no close calls, and the trail was smooth for us. Air down for a smoother ride. Large boulder that sits near the middle of the road is easily passable. Tundra made it with no problems. Puddles at the beginning of the Alma side are deceivingly deep but easily manageable.
Rated 5/5
Visited: 09/09/2022
Difficulty Accuracy: Spot On

Took my Tacoma through the pass Solo. It's definitely doable with low range 4x4. Lockers are not needed. The climb from Alma/Fairplay got challenging about half way up. If you don't have high clearance then picking lines will be important.

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