TOPOGRAPHY. The surface is mostly comprised within the Alleghany Plateau, and has a gentle slope westward and northwestward to the Mis sissippi and Ohio rivers. Its average alti tude is about SOO feet. In the southeastern part the Cumberland and Pine Mountain ridges of the Alleghanies inelude the highest elevations in the State, ranging from 2000 to 3000 feet above the sea, while the intervening valley occu pied by the Cumberland River ranges from 1000 to 1500 feet. The remaining portion of eastern Kentucky is an upland. and has a surface diversi fied by rounded hills and deeply eroded valleys which follow the general northwesterly slope. Between the Cumberland and Green rivers there is an extensive level tract known as the 'Ilarrens'; but the western part, except the portion included in the broad valleys of the Ohio and Mississippi, is gently undulating with low hills.
Kentucky has an extensive drainage system which ineludes innumerable small streams and many navigable waterways. The Mississippi,
flowing a distance of SO miles along the west ern border, receives the entire drainage, but only a small portion of it directly, as most of the streams arc. tributary to the Ohio. The latter. in its winding course of nearly GOO miles along the northern border, is of great commercial MI purtanee; with its affluents, the Tennessee, Cum berland, Green, Salt, Kentucky, and Licking. all of which are navigable, it easy me:xns of communication between remote parts of the State, Only the lower course of the Tennessee lies in Kentucky. The Cumberland flows in its upper and lower courses through the State, but the central portion lies in Tennessee. The Big Sandy on the West Virginia border is navigable only for a short distance, owing to falls. There are no large lakes in the State.