- The North Fork, approximately 28 miles (45 km) long, originates at the outlet of small, rarely visited Lake Kanim, 47°39′41″N 121°28′58″W. Almost directly after exiting the lake it drops over Kanim Falls. The river then flows east before making a wide turn north. Just before its confluence with the Middle Fork the river flows through a canyon near Ernie’s Grove. There are several waterfalls within this canyon including Fantastic Falls.