The Wicomico River is a tributary of the lower tidal portion of the Potomac River located in the U.S. state of Maryland south of Washington, DC. The river empties into the Potomac at Cobb Island and St. Margaret's Island. Its watershed area (excluding water) is , with 2% impervious surface in 1994 in Charles, St. Mary's, and southern Prince George's counties. The lower section of the river forms part of the boundary between Charles and St. Mary's counties. The Wicomico River was designated as a Scenic River under the Maryland Scenic River Act in 1968; Scenic River Commissions oversee it in both Charles and St. Mary's counties (see links below). Tributaries Allens Fresh Run Willmer Creek Cramer Gut Posey Creek Tears Gut Steinhauser Gut Bunker Hill Branch Foggy Bottoms Gut Colby Run Newport Marsh Run Newport Run Hickory Gut St. Clair Gut Murphy Run Hodister Run Lloyd Drain Bowling Gut Budds Creek Chaptico Bay Chaptico Run Burroughs Run Bull Run Maddox Creek Charleston Creek Neale Sound References External links Wicomico Scenic River Commission--St. Mary's County Wicomico Scenic River Commission--Charles County Rivers of Charles County, Maryland Rivers of Maryland Rivers of St. Mary's County, Maryland Tributaries of the Potomac River