Ohio River course forms the northern borders of West Virginia and Kentucky; and the southern borders of Ohio, Indiana and Illinois, until it joins the Mississippi River at the city of Cairo, Illinois. Where the Ohio joins the Mississippi is the lowest elevation in the state of Illinois, at . The Ohio River, which flows westward from Pittsburgh, Pennsylvania, to Cairo, Illinois, is the largest tributary, by volume, of the Mississippi River in the United States. At the confluence, the Ohio is considerably bigger than the Mississippi. Measured by long-term mean discharge in cubic feet per second and cubic meters per second,
River Grove, Illinois River Grove, Illinois River Grove is a village in Cook County, Illinois, United States. The population was 10,227 at the 2010 census. River Grove is located at (41.925830, -87.840135). According to the 2010 census, River Grove has a total area of , all land. Just as nearby Elmwood Park and Oak Park are named after their historic elm and oak trees, River Grove gets its two-part name first from the community's shallow muddy plains river, and second from the majestic groves of American ash trees lining shore of the (Aux) Des Planes River "Bottomland." Credit goes to the village's early