Bismarck Peak is a 7,585-foot summit in Washington’s central Cascades within the William O. Douglas Wilderness and Wenatchee National Forest. East of the Cascade crest and about 24 miles east-southeast of Mount Rainier, it rises in rugged country between Bumping Lake and Rimrock Lake, just south of Mount Aix, its nearest higher neighbor. Together, the two peaks are the highest summits midway between Mount Rainier National Park and Yakima, making them especially prominent in the surrounding landscape. Water from Bismarck Peak flows into tributaries of the Yakima River and ultimately the Columbia River, while its position on the drier east side of the range gives it a rain-shadow climate with cloudier winters and clearer summers.