Helmcken Falls on the Murtle River regularly spews anywhere between 5000 and 25000 cubic feet of water over the falls per second. The river, which stretches to over 300 feet wide at Dawson Falls several miles upstream, is condensed through a notch in the canyon between 50 and 75 feet wide, and is shot 141 meters/ 463 feet into a massive bowl-amphitheater. Wells Gray Provincial Park.