Blacks Fork (also referred to as Blacks Fork of the Green River) is a 175-mile-long (282 km) tributary of the Green River in Utah and Wyoming. The river rises on the northern side of the Uinta Mountains as the combination of three streams draining the area around Tokewanna Peak near the Utah-Wyoming border. Right as the river crosses the Wyoming border, it flows into Meeks Cabin Reservoir which is used for irrigation and flood control.