The Tar River is a river that is approximately 215 miles (346 km) long, in northeast North Carolina flowing generally southeast to an estuary of Pamlico Sound. The Tar River becomes the tidal Pamlico River once it underpasses the U.S. Highway 17 Bridge in Washington, North Carolina.

Pamlico Sound is a large estuarine lagoon in North Carolina. The largest lagoon along the North American East Coast, it extends 80 mi (130 km) long and 15 to 20 miles wide. It is part of a large, interconnected network of similar lagoons that includes Albemarle Sound, Currituck Sound, Croatan Sound, Roanoke Sound, Pamlico Sound, Bogue Sound, Back Sound, and Core Sound known collectively as the Albemarle-Pamlico sound system. With over 3,000 sq. mi. (7,800 km2) of open water the combined estuary is second only in size to 4,479 sq mi (11,600 km2) Chesapeake Bay in the United States.