Back Mountain is a region and former census-designated place (CDP) in Luzerne County, Pennsylvania, United States. It is near the cities of Scranton and Wilkes-Barre. The population was 26,690 at the 2000 census. The area was not delineated as a CDP for the 2010 census. The name "Back Mountain" refers to the area's location behind the mountain ridge forming the northwest side of the Wyoming Valley. The area includes the Lehman Township, the boroughs of Harveys Lake, Dallas, West Wyoming, and a part of Wyoming, and the unincorporated communities (now CDPs) of Trucksville and Shavertown in Kingston Township.