The Guardhouse is a 9,341-foot mountain in Montana’s Glacier National Park, rising along the Continental Divide in the rugged Livingston Range. It is composed of sedimentary rock laid down in ancient shallow seas from the Precambrian through the Jurassic. Its present shape is linked to the Lewis Overthrust, a vast mountain-building event that began about 170 million years ago and pushed a massive slab of older Precambrian rock over younger Cretaceous rock. The peak lies in an alpine subarctic climate with long snowy winters, short cool-to-warm summers, and severe cold. It forms part of a landscape prized for both striking scenery and clearly exposed geology.