The Gates River is a short river in the Lillooet Country of the Southern Interior of British Columbia, Canada. Approximately 14.5 km in length, it flows generally northeast from the outlet of Birken Lake to its mouth at the head of Anderson Lake. Its main tributaries are Haylmore Creek, from the southeast, and Blackwater Creek, from the northwest, which originates near the head of Birkenhead Lake. Augmented by the waters of McGillivray Creek, Lost Valley Creek and others, its flow becomes the Seton River from the foot of Anderson Lake onwards.