The Bella Coola River is a major river on the Pacific slope of the Coast Mountains in southern British Columbia. The town of Bella Coola is at its mouth on North Bentinck Arm. Bella Coola Indian Reserve No. 1 is the location of the main community today of the surviving population of the Nuxalk who gathered there after depredations by smallpox and coloniā¦The Bella Coola River is a major river on the Pacific slope of the Coast Mountains in southern British Columbia. The town of Bella Coola is at its mouth on North Bentinck Arm. Bella Coola Indian Reserve No. 1 is the location of the main community today of the surviving population of the Nuxalk who gathered there after depredations by smallpox and colonialization.