Leadville 100 Course
Sawatch Range, CO
Elevation Profile
Current Conditions
Bottom Line
RED FLAG WARNING in effect today until 8 PM MDT — critical fire weather with gusty SW winds 15-20 mph and low humidity. More pressing for your window: a persistent snow system moves in tonight (74% precip) and parks over the course through Monday with highs only hitting 40-41°F and overnight lows at 19°F. Expect 37 inches of existing snowpack on upper course terrain to get new snow on top, turning trails into post-holing slogs — especially above treeline on Hope Pass and Sugarloaf.
45°/19°F · Mostly Sunny · 1 alert(s)
Low (1/5)
37" depth
Normal flows · 5 gauges
No active fires within 50 miles
13h 37m daylight · Sunrise 6:16 AM · Sunset 7:53 PM
Full Briefing
Today's window is actually usable but compressed. The Red Flag Warning runs until 8 PM MDT — that's dry, gusty air, not a thunderstorm threat, but combined with 15-20 mph WSW winds on exposed ridgelines it'll pull moisture fast. Hydration need today is higher than temperatures suggest. Skies are mostly clear with a 45°F high, so get your miles in this afternoon if you're starting today. The system rolls in tonight and Sunday looks bad: 95% precip probability, snow showers all day, temps topping out at 41°F with sustained SW winds 10-20 mph. That's a miserable running day on a course where you're exposed above 12,000 feet on Hope Pass for a significant stretch.
The snowpack is the quiet complicating factor. Existing depth across the Leadville corridor is substantial — the Long Lake SNOTEL (840 ft elevation listed but likely a data anomaly; treat as a high-elevation reference point) shows 95 inches depth with SWE still nearly 40 inches and trending down via melt. New snow Sunday and Monday will refreeze over what's likely a variable sun-crusted and wind-affected surface on the upper course. Post-holing through breakable crust on Hope Pass at mile 40-50 of a long effort is a serious energy budget problem, not just an annoyance. Lower course sections — Boulevard, Turquoise Lake road — will be runnable but wet.
Avalanche danger is Low (1/5) across all elevations with zero problems identified — that's not a concern for this trip at all. Stream crossings are at normal flows based on available gauge data; no unexpected high water issues anticipated. Fires are clear within 50 miles.
If your goal is quality miles on the actual course, run hard today and into early evening (you have until 7:53 PM sunset). Sunday through Monday is manageable only on the lower segments — Turquoise Lake loop, Fish Hatchery to May Queen section — where tree cover provides some shelter and snow accumulation will be lighter. If you're doing full course segments, Hope Pass is a slog Sunday and Monday — not dangerous, just slow, cold, and hard on legs. Plan Hope Pass for a weather window, not the storm days.
Waypoints
Leadville Start/Finish
Historic 6th Street in Leadville. Race begins at 4 AM.
10,151 ft
Twin Lakes
Major aid station at Twin Lakes. Pacer pickup point outbound.
9,199 ft
Hope Pass Summit
High point at 12,600 ft. The crux of the course, crossed twice.
12,598 ft
Winfield Turnaround
Ghost town of Winfield. Turnaround point for the out-and-back.
10,000 ft
Route Details
Distance
100.0 mi
Elevation Gain
15,748 ft
Elevation Loss
15,748 ft
Max Elevation
12,598 ft
Estimated Days
1.5
Trailhead
Leadville, 6th Street
Best Season
Race held in August. Course runnable July-September at altitude.
About This Route
The Leadville Trail 100 is America's most famous mountain ultramarathon, an out-and-back course through the Colorado Rockies at extreme altitude. The entire course stays above 9,200 feet, with the high point at Hope Pass (12,600 ft) crossed twice—once in each direction. Starting and finishing in historic Leadville (10,152 ft), the course traverses the Sawatch Range through a mix of mining roads, singletrack, and river valleys. The Twin Lakes section, the climb over Hope Pass, and the exposed ridgeline to Winfield turnaround are the signature sections. The altitude is the defining challenge. Even elite runners slow dramatically above 12,000 feet. The 30-hour cutoff is generous by some standards but the altitude makes it brutally selective. Night running through the Colorado mountains adds another dimension. The race has been held since 1983 and is one of the original American ultras.
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