Mountain range, northern Alaska, U.S. It extends about 600 mi (1,000 km) from Kotzebue Sound to the Canadian border.
Its highest peak is Mount Isto, at 9,060 ft (2,760 m). Forming the northwestern end of the Rocky Mountains , it lies within Gates of the Arctic National Park . Huge reserves of oil were discovered at Prudhoe Bay , and the range is crossed at Atigon Pass by the Trans-Alaska Pipeline .