I recently adopted this page. Many changes coming soon. -gimpilator
A historic landmark, the summit of Sourdough was one of the first lookout points established by the United States Forest Service in 1915. Glee Davis built the original lookout in 1917. The present building dating to 1933, was rehabilitated in 1998-99. "Bush" Osborne chose the location to test his fire locating device. The Osborne Firefinder soon became standard equipment in lookouts.
Because the standard route (the Sourdough Mountain Trail) gains 5100 feet in 5.2 miles, the mountain tends to be unpopular with the athletically-challenged. However, it is extremely popular with the athletically-gifted, as the trail represents a steep and strenuous workout. The other route (the Pierce Mountain Approach) is 8.3 miles yet less steep. Because it begins across Ross Lake, it logistically tends to be more difficult.
Getting ThereThe Sourdough Mountain Trail begins behind the domed swimming pool in the town of Diablo, at milepost 126 off State Route 20. The Pierce Mountain route begins 2.5 miles (4 km) from the Ross Dam Trailhead (milepost 134, State Route 20) on Big Beaver Trail.
Red TapeA permit (no charge) is required for all overnight stays in the backcountry. Pets are prohibited in the North Cascades National Park.
When To ClimbThe Sourdough Mountain Trail tends to be climbed in the summer, as the switchbacks are easier to surmount. Climbing out of season is not recommended due to the minor yet still reasonable (and evident towards the summit) avalanche hazard.
CampingCamping is available in two designated camps along Sourdough Ridge. Sourdough Camp is 4.2 miles (6.8 km) from Diablo trailhead and Pierce Mountain Camp is 0.5 mile (0.8 km) NE of the lookout. Bring a stove. Fires are not permitted in the fragile subalpine areas of the National Park.
Mountain ConditionsStop by the Wilderness Information Center in Marblemount (360-873-4500 ext. 39).