Trail Overview

Ensure you acclimate to the altitude before riding the highest road open to motorized vehicles in Colorado. Climb all the way up to 13,185 feet and enjoy the views. Take some pictures of old mine structures on the east side. This trail connects to the difficult Birdseye Gulch trail.

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Difficulty

Moderate. The upper portion of the trail is narrow and rocky on both sides of pass but suitable for aggressive, high-clearance, stock SUVs with low range. Road is closed when blocked by snow, which can occur well into late summer following a hard winter.

History

This short-lived trail was actively used in the 1870s as the quickest way to reach western mining activities. Like so many of these high pass roads, travelers eventually found it easier to take longer but lower routes like Weston Pass. In the late 1870s, Leadville was the most famous silver mining camp in the world, and by the 1890s, it was the second-largest city in Colorado. Today, Leadville is home to the National Mining Museum. The headstone at the summit honors Father Dyer, 'The Snowshoe Itinerant.' Starting in 1861, he spent 29 years preaching at mining camps along the mountains. He became a legend by carrying mail and gold across the pass sometimes twice a day. At least one trip took him 3 days to dig through the snow.

Technical Rating

Joe Caum

Jun 20, 2026

Open

Alma to Leadville. Ascent was great, loose rocks and some small obstacles. Stoped to see Oliver Twist Lake & North London Mine. Track above the mine to the summit the was most difficult. Loose rocks and some off camber sections. Descent from summit to Leadville is tight. Passing oncoming vehicles can be tight. Tundra on 35s. Open diff.

Karen Daniel

Jun 19, 2026

Open

Beautiful day for a drive from Leadville to Alma. Loose rocks pretty much the whole way which made for very slow going. Took longer than I would have liked. Decent view from the top. Glad I did it; probably won’t repeat though.

Xon Baker

Jun 14, 2026

Open

Made the drive from Leadville side in early afternoon. Slow crawling for most of the drive going over loose boulders. The second to last switchback on the west side of the pass was the most difficult part in a full sized tundra on 33’s. Doable but if you’re not keen on heights and steep drop offs not ideal. Overall a beautiful drive.

Ashley Flowers

Jun 14, 2026

Open

Completed Mosquito Pass yesterday from Leadville-Alma in my stock Ram 1500 Rebel. Saw no other vehicles, probably due to starting around 4pm. The switchbacks near the peak on the Leadville side are either eroded or have some new larger rocks in the way, got close to being high centered. Skid plates and a cool head were key, as the trail was narrow with no other line. High wind and snow flurries at the top of the pass. Snow on the ground on the Alma side near the peak. Mildly washed out due to snow melt on the Alma side lower down. Overall beautiful views but felt more difficult than the current rating in several sections.

Alex Fischer

Jun 14, 2026

Open

Went from Leadville to Alma. Snow by the mine on the East side of the pass, easy to go around. Made it over in a stock 4runner with armor getting a few dings but went faster than I should have. Basically an empty trail, only saw one other truck and some SxS's.

goodyt c

Jun 13, 2026

Open

G2g fully open. Tons of snow at North London Mine but you can go around it to continue on trail. Only one other snow spot one mile north of that covering a good portion of the trail, you can go around it but it’s off camber, one slight miscalculation and your driver door slams into a large boulder and your car can roll easy, my driver side was on rock and passenger side was on slush. No more snow after that, made it from start to finish starting at Oliver Twist Lake

GS Pettijohn

Jun 01, 2026

Open

From the east, snow completely blocks the road at North London Mine site. There were melted tracks across the snow but at 4pm it was complete mush. Might be passable at sunrise with hard frozen snow. The shelf appeared to have a track for the low side tires. I could not see past the sharp bend to the south where the road passes through the saddle.

#Evolve Anyways

May 24, 2026

Open

Gate closed

Stephen Calovich

Mar 30, 2026

Open

Signs leading up say the pass is open, but we didn't make it much further than the london mill where the road splits between Pirate Road and Mosquito pass. Deep snow as to be expected. Looks like someone tried but didn't make it far.

Patrick K

Jan 07, 2026

Open

No signs,just a closed gate.

randy Ivie

Oct 19, 2025

Open

My friend and I gained great experience and confidence in our vehicles on this trail. It was equally challenging and rewarding with sight seeing. The rocky obstacles were best handled with aired down tires and I had to be quite specific with my tire placement in many instances. Great history and remnants of a mine. We bypassed the Eisenhower tower tunnel with this trail and made it from Leadville to Alma then to Denver.

Jonathan Garcia

Oct 11, 2025

Open

Trail in good condition. Some drizzle on and small pockets of snow off the trail. Moose present on east side. Very cold at the top, and some water flowing down in small streams.

Nathan Haub

Oct 04, 2025

Open

Trail was dry and clear with some medium difficulty sections, but overall rather easygoing. Hardest part was not hitting your head on the roof of your car due to some of the bumps. But overall great views and mellow day trip for a high clearance 4x4.

Rick Taylor

Oct 02, 2025

Open

was surprised with the rock garden type trail for the east side. & had to 3 point a couple of switchbacks on the west side. no snow on the trail as of yet. beautiful weather. Great views.

Joshua Cordova

Sep 28, 2025

Open

All alone. Great condition. Aspen colors were incredible at the top looking into the valley.