Lenox is set apart from Richmond to the west by a branch of the Berkshire Mountains, with the highest peak in the ridge being Yokun Seat at . To the east, October Mountain rises above the Housatonic River, which flows along that side of town and is impeded by a dam that forms Woods Pond. Contamination with PCBs is highest in the section of the River from Pittsfield to Woods Pond. Parts of the Housatonic Valley Wildlife Management Area and October Mountain State Forest line the river's east banks there. Several marshy brooks also feed into the river throughout town. The town is also home to the Pleasant Valley Wildlife Sanctuary south of Yokun Seat, and the Cranwell Resort and Golf Club.