Breccia Peak is a 6,487-foot summit in Washington’s North Cascades, within the Glacier Peak Wilderness of the Mount Baker-Snoqualmie National Forest. Unlike many nearby peaks, it is the eroded remnant of a stratovolcano, and its name reflects the broken-rock breccia that forms it. The mountain is part of a landscape shaped by volcanic activity, uplift, faulting, and repeated Pleistocene glaciation, which created the region’s sharp ridges and deep valleys. In the marine west coast climate of the western Cascades, heavy precipitation and wet winter snow bring notable avalanche danger. Runoff from the peak flows into tributaries of the Sauk River.