Castor River (Ontario)

The Castor River is a river located in Eastern Ontario, Canada. It flows generally northward through primarily agricultural land, eventually draining into the South Nation River near the town of Casselman. The river is characterized by its slow-moving current and relatively shallow depth.

The river's watershed encompasses a significant portion of the local landscape, and its water quality is of concern due to agricultural runoff and other human activities. Efforts are ongoing to improve the health of the Castor River watershed through best management practices in agriculture and other initiatives.

Historically, the river was used for transportation and milling, although these uses have largely ceased. Today, the river is primarily valued for its role in the local ecosystem and as a recreational resource for activities such as fishing and canoeing, although recreational use is limited due to its shallow depth and water quality.