The river originates at East Head Reservoir, a pond in the Myles Standish State Forest, and flows southwards through various impoundments and cranberry bogs to join the Agawam River near the center of Wareham, Massachusetts, after which it forms the Wareham River, forming Wareham's main harbor with a depth of about .
The river originates at East Head Reservoir in the Myles Standish State Forest and flows south through various water storage areas and wetlands before joining the Agawam River near Wareham's town center in Massachusetts. From there, it forms the Wareham River, which serves as the town's primary harbor with a depth of about .