Colorado trails · High Lonesome Trail
A 12.6-mile out-and-back in Colorado, with 2,456 ft of climbing, topping out at 12,111 ft. Reaches Devils Thumb Pass and other lake/pass destinations. Managed by USFS Sulphur Ranger District.
The climbing leans toward the final third: 46% of the ascent falls between mile 8.4 and mile 12.6. It gives back about 1,536 ft along the way, so it rolls rather than climbing steadily.

USGS 3DEP ELEVATION × ESRI WORLD IMAGERY · VERTICAL ×1.5
Rollins Pass Trailhead — parking nearby. 39.93509, -105.68219 · directions
On August 31, 2026 — the day this page was generated — first light reaches this trailhead at 6:01 a.m., the sun rises at 6:29 a.m. and sets at 7:35 p.m., and the last usable light fades about 8:03 p.m. (MDT) — 13 h 07 min of daylight. At about 2.7 mph plus 30 minutes per 1,000 feet of climbing, the 25.1-mile round trip takes roughly 11 h 45 min, so leaving the trailhead at sunrise puts you back around 6:14 p.m. — 1 h 21 min before sunset.