The East Fork River is a roughly 45-mile (72 km) tributary of the New Fork River in the U.S. state of Wyoming. It flows southwest from the Wind River Range to a confluence with the New Fork south of Boulder.

42°45′3.85″N 109°19′14.68″W / 42.7510694°N 109.3207444°W / 42.7510694; -109.3207444