The Bridge River is an approximately 120 kilometres long river in southern British Columbia. It flows south-east from the Coast Mountains. Until 1961, it was a major tributary of the Fraser River, entering that stream about six miles upstream from the town of Lillooet; its flow, however, was near-completely diverted into Seton Lake with the completion of the Bridg…The Bridge River is an approximately 120 kilometres long river in southern British Columbia. It flows south-east from the Coast Mountains. Until 1961, it was a major tributary of the Fraser River, entering that stream about six miles upstream from the town of Lillooet; its flow, however, was near-completely diverted into Seton Lake with the completion of the Bridge River Power Project, with the water now entering the Fraser just south of Lillooet as a result.