Located at the west end of the Brooks Range, extends west from Uivaksak Creek and the head of the Kuna River. 150 miles long.
Named in 1886 by Lieutenant G. M. Stoney, U.S. Navy (USN), for Lieutenant Commander George Washington De Long, U.S. Navy (USN). See De Long Islands.
Kingaviksak Mountain, Misheguk Mountain, Nucleus Mountain, Poko Mountain, Siniktanneyak Mountain, Sphinx Mountain, Stone Hut Peak, Tupik Mountain, Wulik Peaks,
Iggiruk Mountains, Imikneyak Mountains, Poktovik Mountains,