Mount Custer is an 8,888-foot peak on the Continental Divide in Glacier National Park’s Livingston Range, rising more than 3,300 feet above Lake Nooney with Herbst Glacier just northeast of its summit. Probably named for George Armstrong Custer, it reflects both human association and deep geologic history. The mountain is made of sedimentary rock deposited from the Precambrian to the Jurassic in ancient shallow seas, and its present form is linked to the Lewis Overthrust, which began about 170 million years ago when older rock was thrust over younger Cretaceous layers. Its subarctic climate brings long, bitterly cold winters, short summers, and severe alpine conditions.