The Ohio River is approximately 981 miles in length. It begins in Pittsburgh and ends in Cairo, Ill., emptying into the Mississippi River. The Ohio River either travels through or borders the states of Illinois, Indiana, Kentucky, Ohio, Pennsylvania and West Virginia.
The Ohio River is the largest tributary of the Mississippi River, and it is actually larger in volume than the Mississippi at its confluence. Ohio's drainage basin touches parts of 14 states. There are 20 dams on the Ohio River, and they are operated by the Army Corps of Engineers. The Ohio river is naturally shallow, and depth was added artificially by the 20 dams to eliminate insufficient trenches. The depth in its natural state varied from 3 to 20 feet prior to the implementation of dams. The dams made commercial navigation possible and also provided great economic offerings.
The Ohio River was ranked the most polluted river in the United States in 2010. There have been over 160 different species of fish identified in the Ohio River, but the dams interfere with the natural cycle of numerous organisms by preventing them from moving up and down the streams. The dams have drastically altered the natural habitat of many different organisms.