Sourdough Mountain Lookout

Sourdough Mountain Lookout is a one-story wooden fire lookout on the rocky summit of Sourdough Mountain above Diablo Lake. The cabin is closed to public entry, so the draw is the summit and its history rather than a chance to go inside. From Diablo, the usual approach is 5.2 miles one way with 4,870 feet of climbing; this is one of the park’s most strenuous hikes, not a quick overlook.

The route spends its first 3.5 miles climbing through forest before the grade eases into subalpine meadows. The last 1.5 miles cross open meadow and ridge to the lookout. On a clear day, Diablo Lake lies far below, with Mount Baker, glaciers and peaks all around. Fog can hide the panorama. For a photo, frame the cabin on its rocky perch with the peaks behind it; the outcrop gives the summit a real sense of exposure.

Sourdough became one of the Forest Service’s early lookout points in 1915. Glee Davis built the first lookout here in 1917; the present cabin dates to 1933 and was rehabilitated in 1998–99. “Bush” Osborne chose this summit to test his fire-locating device, which led to the Osborne Firefinder becoming standard equipment at lookouts. The cabin is a historic landmark to see from outside, not a room visitors can enter.

Poets Gary Snyder and Philip Whalen worked as lookouts here in the 1950s, and both found inspiration in the mountain. The upper meadows also support wildflowers, birds, small mammals, deer and black bears; these are possibilities, not sightings to count on.

The Diablo trailhead starts behind the domed swimming pool; parking is by the river across the road. There are few or no water sources during the first 3.5 miles, so carry water and enough food for the climb and return. Early-season snow brings route-finding hazards, and snow bridges over Sourdough Creek can weaken and collapse.