Denman Mountain is a Catskill peak in Sullivan County, New York, north of Grahamsville. It is the highest peak within the Sullivan County portion of the Catskill Mountains, giving it a distinct place in the county’s landscape. Nearby, Sugarloaf Mountain lies to the east-southeast and Blue Hill to the west-northwest. Although some mapping in the app shows it as a hill, local understanding places it within the broader mountain terrain that characterizes this part of the Catskills.