Frisco Mountain is a 7,760-foot summit in northern Washington’s Cascade Range, near Rainy Pass on the border of North Cascades National Park and the Stephen Mather Wilderness. First climbed in 1926 by surveyor Lage Wernstedt, it took its name from a mining claim worked on its south side in the 1920s. Its runoff feeds Rainy Lake and tributaries of Bridge Creek, and the Lyall Glacier in its northeast cirque sends water over falls dropping about 1,000 feet to the lake below as the glacier retreats. The peak stands in a wet maritime mountain climate and in a landscape shaped by tectonic activity, uplift, terrane accretion, and Pleistocene glaciation.