The northernmost unit in the National Park System lies entirely above the Arctic Circle and encompasses the central Brooks Range — 8.5 million acres with no roads, no trails, and no visitor facilities, reached only by small aircraft from Fairbanks or Coldfoot. Named by explorer Robert Marshall in 1929 for two peaks he saw as the "Gates to the Arctic," the preserve is one of the most remote places on Earth, with an average of fewer than 11,000 visitors per year.