Stage 2 · Leadville to Alma and back
Queen stage: Mosquito Pass
Two crossings of North America's highest through-road; where the overall is decided.
Indicative candidate route, not a final course. Lines follow real public roads, but the final course depends on land-manager permits, the safety plan and the landowner. Distances and climbing are approximate.
The route
The stage leaves Leadville on 7th Street, which becomes Mosquito Pass Road, and climbs up Evans Gulch to the pass. It descends the Park County side through Mosquito Gulch on County Road 12 to Colorado 9 below Alma, turns, and climbs back over the pass to Leadville.
| Distance | ≈ 35 mi (candidate line) |
| Climbing | ≈ 5,800 ft (sum of gains, USGS elevations) |
| High point | Mosquito Pass, 13,185 ft (crossed twice); highest sampled point 13,155 ft |
| Surface | Pavement leaving town, then dirt on Mosquito Pass Road (Lake County Road 3 and Park County Road 12). Loose rock and stream crossings above treeline; a four-wheel-drive road. About 90% unpaved by OpenStreetMap surface tags. |
| Start | Leadville, Harrison Avenue |
| Finish | Leadville, Harrison Avenue |
| Aid, cutoff, crew and alternates | Race operations for this stage, below |
Map and profile
Terrain view centered on Mosquito Pass. Google's driving directions will not route over this four-wheel-drive road and detour by way of Breckenridge, so no route is drawn here. Use the elevation profile and the KML for the candidate line.
Elevation profile
Miles (x) and feet (y). Elevations sampled every 300 m from the USGS 3DEP elevation service along the candidate line. Approximate.
ProposedPlanned aid
Every location below is a candidate, subject to permits, land-manager approval and the safety plan. The proposed support model is self-supported with neutral aid, fully swept: riders carry what they need between aid points, aid stations are neutral, and a sweep follows the last rider.
| Candidate location | Approx. mile | Services | Crew access |
|---|---|---|---|
| Evans Gulch on Mosquito Pass Road, below treeline (candidate) | about 5 | Water, radio | No |
| Mosquito Pass summit, first crossing (candidate) | about 8 | Water, food, medical, radio | No |
| Park County Road 12 at Colorado 9, below Alma (turnaround) (candidate) | about 17 | Water, food, mechanical, medical | Yes |
| Mosquito Pass summit, second crossing (candidate) | about 27 | Water, medical, radio | No |
ProposedCutoff basis
Candidate cutoff at Park County Road 12 at Colorado 9, below Alma (turnaround). The second climb takes riders back above 13,000 feet. The turnaround cutoff exists so no one starts that climb late enough to be on the summit ridge when afternoon thunderstorms build. Times will be set in the course design with the medical plan.
IllustrativeTo show the scale: Park County Road 12 at Colorado 9, below Alma (turnaround) is about 17.4 miles into the stage. If a cutoff there fell 3.5 hours after the start, a rider would need to average about 5.0 mph, stops included, to make it. That window is an illustration for planning, not a proposed cutoff time.
ProposedCrew access
Candidate crew zones, subject to permits and road access. Some high sections will have no crew access. The table above marks which candidate aid points a crew could reach by ordinary vehicle. See crew and support for how crews would work.
PendingFire and closure note
No closure is known to affect this stage's roads as of September 2026, but conditions for 2027 are unknown. Like every stage, it follows land-manager closure orders and the smoke and air-quality go/no-go described on the course page.
Under considerationBad-weather or closure alternate (candidate)
Evans Gulch hold. If lightning, snow or a closure keeps the field off the summit, the stage would hold at a candidate turnaround below treeline on Mosquito Pass Road (Lake County Road 3) in Evans Gulch, about mile 5 at roughly 11,300 feet, and race as a repeated climb from Leadville with no crossing to the Park County side. Any alternate is subject to permits, sanctioning and insurance, and the rules for shortening a stage are in the rules and policies.
ProposedGPX
Indicative candidate route, not for race-day navigation. The line follows public roads from OpenStreetMap data and will change with permits and the safety plan.
How it races
This is the stage the week is built around. The first climb from Leadville is long and gets rougher as it goes, with the last miles above treeline on loose rock. Some riders will walk short pitches near the top, and that is normal on this road.
The descent to the Alma side is fast but technical, and the climb back up from Mosquito Gulch is where the gaps open. Riders who spent too much on the first crossing can lose several minutes on the second.
The final descent into Leadville on the same road rewards riders who can handle rocks when tired. Weather is part of the stage: afternoon lightning above treeline is common in summer, which is why the cutoffs sit early.
History of the road
The pass sits on the Mosquito Range between Lake and Park counties, on the divide between the Arkansas and South Platte rivers. It is usually cited as the highest through-road in North America, and today it is passable only on foot, by bicycle or off-road motorcycle, or in a proper four-wheel-drive vehicle, and usually only in summer.
Before there was a road, the Methodist preacher John Lewis Dyer crossed the pass on foot and on snowshoes in the 1860s, carrying mail between the mining camps. A memorial to him stands at the summit.
A toll wagon road opened over the pass in 1879, at the height of the Leadville silver boom. Freight wagons and stagecoaches ran between Fairplay, Alma and Leadville over it, and the harsh conditions earned it the nickname "Highway of Frozen Death." Traffic fell away after the railroad reached Leadville in 1880, and the road was left to the mines and, later, to recreation.