The Patuxent River is a tributary of the Chesapeake Bay in the state of Maryland. There are three main river drainages for central Maryland: the Potomac River to the west passing through Washington, D.C., the Patapsco River to the northeast passing through Baltimore, and the Patuxent River between the two. The 908-square-mile Patuxent watershed had a rapidly growing population of 590,769 in 2000.