Tower Mountain, in the Catskill Mountains east-northeast of Deposit in Delaware County, is chiefly associated with the Rock Rift Fire Observation Tower, a Civilian Conservation Corps-built fire tower first staffed in 1935. The 72-foot-9-inch International Derrick Company structure is notable for its 1933 design, including nine-pane pivoting cab windows and an unusual corner-to-corner stair arrangement. The name Rock Rift preserves the memory of a nearby hamlet lost during creation of the Cannonsville Reservoir, when New York City acquired communities by eminent domain and submerged or removed homes, churches, schools, and businesses. Fire lookout service ended after the 1988 season, and restoration is planned.