Frisco Mountain is a mountain summit in the Cascade Range in the U.S. state of Washington. It is located two miles southwest of Rainy Pass on the borders of the Stephen Mather Wilderness and North Cascades National Park. The mountain derives its name from a mining claim on the south side (Bridge Creek side) that was worked in the 1920s. Its nearest higher peak is Rainy Peak, to the east-southeast. Precipitation runoff from Frisco Mountain drains into Rainy Lake and tributaries of Bridge Creek. The retreating Lyall Glacier in its northeast cirque contributes to waterfalls which tumble into Rainy Lake.