The river flows 135 kilometers south from about 200 metres south of Mazinaw Lake into Kennebec Lake near the community of Arden, part of Central Frontenac, Frontenac County, through a chain of small lakes and through part of Lennox and Addington County to the Bay of Quinte on Lake Ontario near the community of Shannonville, part of Tyendinaga, Hastings County.