River Calder, Wyre

River Calder
The River Calder, near its source
Physical characteristics
SourceFiendsdale Head
  locationForest of Bowland, Lancashire
  coordinates53°55′50.6″N 2°38′14.4″W / 53.930722°N 2.637333°W / 53.930722; -2.637333
  elevation1,440 feet (440 m)
MouthBarnacre-with-Bonds
  location
Catterall
  coordinates
53°52′55.1″N 2°46′28.8″W / 53.881972°N 2.774667°W / 53.881972; -2.774667
  elevation
43 feet (13 m)
Length13 mi (21 km)
Basin size28 km2 (11 sq mi)

The River Calder is a 13-mile (21 km) long river that is one of the main tributaries of the River Wyre in Lancashire, England. Like the other rivers in England with the name Calder, its name is thought to derive from a mixture of Old Welsh and Old British words meaning "hard and violent water or stream".