The Coal Region is a historically important coal-mining area in Northeastern Pennsylvania in the central Ridge-and-valley Appalachian Mountains, comprising Lackawanna, Luzerne, Columbia, Carbon, Schuylkill, Northumberland, and the extreme northeast corner of Dauphin counties. Academics have made the distinction between the North Anthracite Coal Field and the South Anthracite Coal Field, the lower region bearing the further classification Anthracite Uplands in physical geology. The Southern Coal Region can be further broken into the Southeastern and Southwestern Coal Regions, with the divide between the Little Schuylkill and easternmost tributary of the Schuylkill River with the additional divide line from the Lehigh watershed extended through Barnesville the determining basins.