Oyster River (New Hampshire)

Oyster River
Oyster River at head of tide in Durham, New Hampshire
Location
CountryUnited States
StateNew Hampshire
CountyStrafford
TownsBarrington, Lee, Madbury, Durham
Physical characteristics
SourceCreek Pond
  locationBarrington
  coordinates43°10′3″N 71°1′58″W / 43.16750°N 71.03278°W / 43.16750; -71.03278
  elevation205 ft (62 m)
MouthLittle Bay
  location
Durham
  coordinates
43°7′21″N 70°52′4″W / 43.12250°N 70.86778°W / 43.12250; -70.86778
  elevation
0 ft (0 m)
Length17.0 mi (27.4 km)
Basin features
Tributaries 
  leftCollege Brook, Beards Creek, Johnson Creek, Bunker Creek
  rightCaldwell Brook, Chelsey Brook, Longmarsh Brook

The Oyster River is a 17-mile-long (27 km) river in Strafford County, southeastern New Hampshire, United States. It rises in Barrington, flows southeast to Lee, then east-southeast in a serpentine course past Durham to meet the entrance of Great Bay into Little Bay. The bays are tidal inlets of the Atlantic Ocean, to which they are connected by a tidal estuary, the Piscataqua River. The freshwater portion of the river is 14.1 miles (22.7 km) long, and the tidal river extends 2.9 miles (4.7 km) from Durham to Great Bay.

The Oyster River reaches tidewater at the base of a dam in the center of Durham, just west of the river's crossing by NH Route 108. Due to siltation, the river is only fully accessible to motorized boats west of the Durham Water Plant for approximately three hours on either side of high tide. Boaters have noticed the increasing effect of siltation on navigation since 1998.