Cairn Mountain is a 12,205-foot summit in Montana’s Beartooth Mountains within the Absaroka-Beartooth Wilderness of Custer National Forest. Located 1.24 miles south of Granite Peak, it lies beside the highest mountain in the state and forms part of one of Montana’s most prominent alpine landscapes. Its importance comes chiefly from this setting in the high, rugged Beartooth terrain and from its close relationship to Granite Peak, placing it among the neighboring summits that define this wilderness area.