The river has a rich history. The
Dene and
Sekani First Nations used it for food and trade. The river itself is named for the town of
Fort Nelson, established in 1805 by the
North West Company as a
fur trading post near the river's junction with the
Muskwa River. With the abandonment of the village and trading post at
Nelson Forks and Fort Nelson's relocation roughly eight kilometres southwest up the Muskwa River to better access the
Alaska Highway built in the 1940s, there are no longer any communities along this river. The Fort Nelson River is formed at the confluence of
Sikanni Chief River and
Fontas River, at an elevation of . It flows north-west and north, and its course is paralleled by
BC Rail tracks north of
Fontas. It receives waters from the Elleh Creek and Klua Creek, then follows a north-west direction, a short distance from
Andy Bailey Provincial Park. It turns north again near Fort Nelson, where the
Muskwa River flows into it. Further north it receives the
McConachie Creek, Cridland Creek and
Sahtaneh River, which also carries waters from the Snake River. It then turns north-west and west, where it receives the Shush Creek, Onion Creek, Tsimeh Creek, Stanolind Creek and Kiwigana River. It is then crossed by the
Liard Highway and continues westwards, receiving waters from Tsoo Creek, Etane Creek, Obole Creek and Capot-Blanc Creek. It flows into the
Liard River at
Nelson Forks, at an elevation of . Its waters are carried up the Liard River then the
Mackenzie River, into the
Arctic Ocean. == Local disagreement ==