The Cumberlan Plateau is the southern part of the Appalachian Plateau. It includes much of eastern Kentucky and western West Virginia, part of Tennessee, and a small portion of northern Alabama. The terms "Allegheny Plateau" and the "Cumberland Plateau" both refer to the dissected plateau lands lying west of the main Appalachian Mountains. The terms stem from historical usage rather than geological difference, so there is no strict dividing line between the two. Two major rivers share the names of the plateaus, with the Allegheny River rising in the Allegheny Plateau and the Cumberland River rising in the Cumberland Plateau.