Castor River North and South are two separate communities on either side of the mouth of Castor River that flows into St. John's Bay. The river was named by the French in 1735. Castor is the Latin word for "Beaver". Castor River North is a site for salmon fishing. It is an angler's challenge and is visited by many sport fishermen/tourist every year.

It is scenic area and a place to enjoy the outdoors. Castor River flows west from the Long Range Mountain for 100 km to its mouth in St. John's Bay.

It is reported that the first settlers to Castor River was Jesse Humber and his family. In 1888 a Mr. Shearer of Nova Scotia moved into Castor River North and setup a lobster cannery. By 1945 both communities began to grow and prosper and were recorded as having sixty-five families. In 1981 the communities began to separate with two different local communities, two schools, and two churches.

Community and business services for Castor River North include a K-12 school, Viking Trail Academy (located 22 kms north in Plum Point). Health care is provided in Port Saunders (49 kms south). A Canada Post Mail Box is available. Community, recreational and other business services are found in the towns of Port Saunders, Port au Choix and Hawkes Bay 49 kms to the south or Plum Point 22 kms to the north.