Green Mountain is a 4,824-foot summit in King County, Washington, on the western edge of the Cascade Range within Mount Baker-Snoqualmie National Forest. More notable than its absolute elevation is its steep rise above the surrounding land. It stands near Mount Teneriffe, with Moolock Mountain as the nearest higher summit, and its runoff drains into tributaries of the Snoqualmie River. The mountain and its surroundings reflect the marine west coast climate of this part of Washington, with heavy rain and snow brought from the Pacific. Its deep valleys and rugged terrain were shaped over time by uplift, faulting, and repeated glaciation during the Pleistocene.