Monument Mountain is a quartzite ridgeline in the Berkshires of western Massachusetts, spanning Great Barrington and Stockbridge. Its most noted feature is the open crest of Peeskawso Peak, with landmarks including Devil’s Pulpit, Flag Rock, and a waterfall along the Hickey Trail, and its overlooks take in the Housatonic River Valley, the Berkshires, the Taconic Mountains, and the Catskills. The mountain’s slopes form a small watershed divide, and the reservation draws more than 20,000 visitors each year. It also holds a notable literary connection: in August 1850, Herman Melville, Nathaniel Hawthorne, and Oliver Wendell Holmes Sr. climbed it together.