Class II-III North Fork Fortymile River, AK

The upper North Fork is a narrow, entrenched river, with few gravel bars. The uplands are dominated by open, moist tundra areas with little terracing. This section is extremely remote. It is reachable by helicopter,or fixed-wing aircraft into a private airstrip on a ridge above Slate Creek and a 3 mile portage to floatable water. This section can also be reached during periods of high water by floating down Slate Creek from the Gold Run airstrip, 17 miles upstream. The river is swift, with numerous small rapids, and requires normal to high water for boating. The stream gradient is approximately 18 feet per mile. There are several habitable cabins in this stretch used for winter trapping purposes. (Bureau of Land Management) rivers.gov