Miller Mountain is a 10,494-foot summit in the Beartooth Mountains of southern Montana, near Cooke City in Custer-Gallatin National Forest and the historic New World Mining District. Rising about 2,000 feet above Sheep Creek in one mile, it is notable for its steep relief and for drainage that feeds both the Stillwater River headwaters and the Lamar River system. Its rocks include gabbro, Miocene breccia, and Eocene monzonite porphyry. The mountain was named for trapper Adam “Horn” Miller, one of four men credited with discovering and naming the New World Mining District in 1869, and the Shoo Fly Mine on its south slope produced gold, copper, and lead-silver ore before closing in 1893.