MUSSELS OF CUMBERLAND RIVER AND TRIBUTARIES. 5 



is nearly 750 miles. Its principal tributaries are the Laurel and Rock- 

 castle Rivers from the north, which join it within a few miles of each 

 other at the southwestern corner of Laurel County, Ky.; the Big 

 South Fork, whose mouth is at Burnside, Ky.; the Obey River from 

 the south at Celina, Tenn.; Roaring River, from the south, at Gaines- 

 boro Landing, Tenn. ; Caney Fork, from the south, at Carthage, 

 Tenn.; Stones River, from the south, 15 miles above Nashville, 

 Tenn.; Harpeth River, from the south, at Pardue, Tenn.; and the 

 Red River, from the north, at Clarksville, Tenn. 



The Cumberland is navigable during high water from its mouth to 

 Burnside, Ky., a distance of 525 miles, and a system of locks is in 

 process of construction which will make navigation possible during 

 the entire year. 



PHYSIOGRAPHY. 



The area drained by the river and its tributaries is about 25,000 

 square miles, and embraces mountain ranges, a continental plateau 

 (the Cumberland Plateau), and lowlands. Along the upper reaches 

 of the river amorg the Cumberland and Pine Mountains in the eastern 

 portion of the plateau the rocks are largely Cambrian sandstone; 

 through the remainder of the plateau and the long stretch of lowlands 

 they are almost universally limestone. The dividing line is at 

 Cumberland Falls in the western part of Whitley County, Ky., where 

 the river plunges over a wall 85 feet in height. From the source to 

 the falls the river has nowhere cut its channel very deep; below the 

 faUs, and especially through the plateau, the banks are Uned almost 

 continuously with high limestone cliffs, filled with caves and roughly 

 weathered. The faces of these cliffs furnish abundant evidence of past 

 upheavals in numerous faults and contortions of the strata, as well 

 as in repeated antichnal and syncHnal folds, differing considerably 

 in intensity at different localities. 



Above the falls the river valley is comparatively narrow, but below 

 the falls it widens somewhat, and the river winds back and forth in 

 broad and then in shorter curves, with cUffs now on one side and now 

 on the other. 



So evenly has the channel been worn down through the soft lime- 

 stone that there are no rapids of any importance below the f aUs, and 

 steamboats can run from the mouth up to Burnside in Pulaski 

 County, Ky., within comparatively few miles of the falls, as already 

 stated. This makes the river easy to navigate for two-thirds of its 

 entire length, and since it runs through a great region remarkable for 

 its mineral and agricultural resources and its large forests, but with a 

 physical contour which makes the building of raihoads exceedingly 

 expensive, the Cumberland is destined to be one of the most important 

 commercial highways of the United States. 



