Kentucky and Illinois are the two states that border both the Ohio and the Mississippi Rivers. The junction of these two river systems is located near Cairo, Illinois, historically a busy river port.
The section of the Mississippi below the Ohio River junction is referred to as the Lower Mississippi. The Ohio more than doubles the water flow of the Mississippi. Between this contribution and the contributions of several other smaller rivers downstream, the Lower Mississippi is more than a mile wide in several areas until it reaches the Louisiana delta region.
Though only two states border both major rivers, the Mississippi contains waters that drain from 31 states and two Canadian provinces. Except for several small Gulf Coastal rivers and waters that drain into the Great Lakes and Hudson Bay, all runoff water between the Rocky Mountains and the Appalachian Mountains drains into the Mississippi.