Klamath National Forest · California
Middle Boulder
3.1 mi of trail, end to end · native material surface · trail No. 5577 · trail class 3 · typical grade 12-20% · tread 18-24 inches wide
Trailhead Middle Boulder Trailhead Drive there
Middle Boulder Trailhead the Forest Service's write-up
Access this trailhead by following Forest Road 40N17 from Callahan.
The trailhead offers several options. Visit the Cement Banks Geological Area adjacent to the trailhead. Or follow Trail #5577 in to the Trinity Alps Wilderness to the Pacific Crest Trail. Branch off on Trail #5576 to Telephone Lake and Eagle Peak before reaching the PCT. Or loop around on Trail #5582 to East Boulder Lake and back to the PCT on Trail #5575.
This trailhead on fs.usda.gov
Every trail in Klamath National Forest
About this trail's facts
The lines are the US Forest Service's National Forest System trails layer (public domain), read 2026-10-16 and simplified for the map; the length is the line's, end to end, and the class, surface, grade and tread width are the forest's own entries where it publishes them - a forest that publishes the centreline alone has none. The trailheads and the points along the way are the Service's recreation points, and the write-ups its own recarea text, unedited. Heights come from USGS 3DEP through Terrain Tiles on AWS (Mapzen/Tilezen), read along each line and rounded; a short trail on steep ground can be off by a few tens of feet. Closures change: check the forest's own site before you go.
