The year was 1944. World War II was show­ing signs of winding down, but predictions that the Japanese would fight to the bitter end had the Allies gravely concerned that they would run out of gasoline for the war effort. The 23-million-acre Naval Petroleum Reserve in northern Alaska was a prime location for finding new sources of oil, and the U.S. Navy decided to explore. But the navy had a problem: no maps. So it decided to take an exceptionally detailed set of aerial photographs.