The Fort Nelson River is located in north-eastern British Columbia, Canada. It flows 517 km generally north-westward to the Liard River, a tributary of the Mackenzie River, which empties into the Arctic Ocean. The river drains a watershed of 55,900 square kilometers and is formed by the confluence of the Fontas River flowing from the east, and the Sikanni Chief River flowing from the south. These, along with the Sahtaneh and Muskwa Rivers constitute the major tributaries.