Pinnacle Peak is a mountain summit in the North Cascades Range of Washington, United States. It is located within North Cascades National Park, between Pyramid Peak and Paul Bunyans Stump, which is the nearest higher peak. It rises steeply from Diablo Lake, one of the reservoirs on the Skagit River. It is part of a group of peaks that form the northern end of a chain running south through climbing destinations such as Colonial Peak and Snowfield Peak. Like many North Cascade peaks, Pinnacle Peak is more notable for its large, steep rise above local terrain than for its absolute elevation. Precipitation runoff from the mountain drains into Diablo Lake and Skagit River. The approach is via the Pyramid Lake Trail, starting near Diablo Dam on the North Cascades Highway. From the lake, there is route-finding up Pyramid Arm to Colonial Glacier.