North Cascades National Park hiking guide
Thornton Lakes Trail
A 9.1-mile out-and-back with 2,950 ft of climbing in Ross Lake & Diablo Lake, rated difficult.
Key facts
- Length
- 9.1 mi (14.6 km)
- Elevation gain
- 2,950 ft (899 m)
- Route type
- Out and back
- Difficulty
- Difficult
- Area
- Ross Lake & Diablo Lake
- Highest point
- 4,998 ft
- Lowest point
- 2,506 ft
About Thornton Lakes Trail
The first stretch follows an old road grade through brushy regrowth, then climbs through mature hemlock forest and heather meadows to a ridge with views of Triumph Peak and the lower lake. The descent is steep and often muddy, with a scramble over rocks and floating logs at the lake's outlet, so take your time. For more experienced hikers, a scramble up Trappers Peak offers wide views across the North Cascades.
Route map
This route was checked by Parka editors.
