Stage 4 · Leadville loop over Turquoise Lake
Rail-grade day: Hagerman Pass
Steady climbing near the old Colorado Midland grade to the Divide; a rhythm stage.
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 route follows Turquoise Lake Road west past Sugar Loaf Dam and turns onto Hagerman Pass Road, which climbs along Busk Creek to the pass on the Continental Divide. It returns down the same road, rounds the west end of the lake and comes home along the north shore.
| Distance | ≈ 38 mi (candidate line) |
| Climbing | ≈ 3,500 ft (sum of gains, USGS elevations) |
| High point | Hagerman Pass, 11,925 ft; highest sampled point 11,975 ft |
| Surface | Paved Turquoise Lake Road to the start of Hagerman Pass Road (Lake County Road 4, Forest Road 105), then graded dirt that turns rocky in the final miles. The top is a four-wheel-drive road. About 40% 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
Google's driving route for the outbound leg: Leadville, Sugar Loaf Dam and Hagerman Pass Road to the summit (about 15.8 miles). The candidate line returns the same way and comes home along the north shore.
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 |
|---|---|---|---|
| Sugar Loaf Dam, Turquoise Lake Road (candidate) | about 5 | Water | Yes |
| Hagerman Pass Road near the Busk Creek crossing (candidate) | about 10 | Water, food, medical | No |
| Hagerman Pass summit (candidate) | about 16 | Water, medical, radio | No |
| West end of Turquoise Lake, on the return (candidate) | about 26 | Water, food, mechanical | Yes |
ProposedCutoff basis
Candidate cutoff at Hagerman Pass summit. The top of Hagerman Pass is exposed and the last miles are rocky. A summit cutoff keeps the field moving back below treeline before the usual afternoon thunderstorms. Times will be set in the course design with the medical plan.
IllustrativeTo show the scale: Hagerman Pass summit is about 15.7 miles into the stage. If a cutoff there fell 2.75 hours after the start, a rider would need to average about 5.7 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
This stage sits in the 2026 Willow Fire area. The fire started on June 28, 2026, about six miles west of Leadville, and burned about 7,200 acres south of Turquoise Lake toward Mount Massive. It forced the 2026 Leadville Trail 100 MTB off Hagerman Pass Road, Sugarloaf Mountain and Powerline and onto the north side of Turquoise Lake. Hagerman Pass Road reopened in August 2026, but a Forest Service closure order for lands south of the lake ran through September 30, 2026. Post-fire closures, burn-area hazards and flood risk for 2027 are unknown. This stage runs only if land managers allow it, and the alternate below is planned from the start.
Sources: VeloNews on the 2026 LT100 MTB reroute, Vail Daily on the Willow Fire, Forest Service closure order, Lake County fire page.
Under considerationBad-weather or closure alternate (candidate)
Turquoise Lake north-shore alternate. Hagerman Pass Road and the south side of the lake are dropped. The stage runs out of Leadville on the north-shore Turquoise Lake Road (Lake County Road 9) to the west end of the lake and back, with candidate gravel spurs north of the lake on Kevin Gulch Road (Forest Road 103), whose surface still has to be surveyed. It uses the side of the lake the 2026 LT100 MTB used when the fire closed Hagerman. 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
The climb is long and consistent for most of its length. That favors riders who can hold a steady effort at altitude, and it is the day for a strong climber to take time without the chaos of Mosquito.
The final stretch to the pass steepens and gets rockier. The descent back to the lake is fast on a graded surface, and the paved north shore run into Leadville rewards riders who work together.
It is also the stage with the most history visible from the bike. The route passes below the east portals of both railroad tunnels, and the old grade is visible from the road.
History of the road
The pass is named for James J. Hagerman, who controlled the Colorado Midland Railway. The Midland was the first standard-gauge railroad built across the Continental Divide in Colorado, running from Colorado Springs through Leadville and over the Divide here toward Glenwood Springs and Grand Junction.
The first crossing was the Hagerman Tunnel, opened in 1887. It was 2,161 feet long at an elevation of 11,528 feet and was approached on the east by a wooden trestle 1,084 feet long. The railroad replaced it in the early 1890s with the lower, more direct Busk-Ivanhoe Tunnel, 9,394 feet long at 10,953 feet.
The Midland ceased operating in 1918. In 1922 the Busk-Ivanhoe bore reopened to cars as the Carlton Tunnel, a toll tunnel on the state highway, until the state stopped maintaining the road in the early 1940s. Since 1921 the tunnel has also carried water from Ivanhoe Lake on the west side into the Arkansas basin, a use that continues. The Shoshone Transmission Line, built over the pass in 1909, is still in use.