Colorado trails · Arapaho Pass Trail
Arapaho Pass Trail
A 10.2-mile out-and-back in Colorado, with 3,612 ft of climbing, topping out at 11,953 ft. Reaches Arapaho Pass and other lake/pass destinations. Managed by USFS Sulphur Ranger District.
Elevation profile
Most of the climbing sits in the final third — 56% of the ascent, between mile 6.8 and mile 10.2. It climbs almost continuously, with little descent to recover on.
3-D terrain
USGS 3DEP ELEVATION × ESRI WORLD IMAGERY · VERTICAL ×1.5
Reaches
- Arapaho Pass (pass)
- Caribou Lake (lake)
- Monarch Lake (lake)
Heads up
Getting there
Monarch Lake Trailhead — parking nearby, restroom, fee site. About 1 h 58 min drive (77 mi, 9 of them unpaved) from Silverthorne. 40.11137, -105.74718 · directions
Daylight at the trailhead
On October 14, 2026 — the day this page was generated — first light reaches this trailhead at 6:45 a.m., the sun rises at 7:12 a.m. and sets at 6:25 p.m., and the last usable light fades about 6:52 p.m. (MDT) — 11 h 13 min of daylight. At about 2.7 mph plus 30 minutes per 1,000 feet of climbing, the 20.4-mile round trip takes roughly 11 h 09 min, so leaving the trailhead at sunrise puts you back around 6:21 p.m. — 4 min before sunset.
Loop options
- Arapaho Pass Trail + Arapaho Pass Spur Trail + Cascade Creek Trail — 5.6 mi loop, 370 ft gain
Nearby trails
- North Inlet-Flattop Junction Trail — 10.6 mi
- High Lonesome Trail — 12.6 mi
- Tonahutu Creek-Flattop Junction Trail — 14.8 mi
- East Longs Peak Trail — 15.0 mi