Battlement Mountain is an 8,830-foot peak in the Lewis Range of Glacier National Park, Montana, with Lake Isabel to its northeast. Like many mountains in Glacier, it is composed of sedimentary rock deposited from the Precambrian through the Jurassic in ancient shallow seas. Its present shape is linked to the Lewis Overthrust, a major geologic event that began about 170 million years ago, when a massive slab of older Precambrian rock about 3 miles thick, 50 miles wide, and 160 miles long was thrust over younger Cretaceous rock. The mountain lies in an alpine subarctic climate with long, snowy winters, cool to warm summers, and severe cold and wind chill in harsher weather.