Eager to investigate rumors of land north of Alaska, Ernest deKoven Leffingwell and Ejnar Mikkelsen organized the 1906 Anglo American Polar Expedition. Despite extreme conditions, they determined the edge of the continental shelf--a significant geographic discovery. Leffingwell remained behind, and with substantial assistance from his Inupiat neighbors, the driven young geologist explored, surveyed and documented geography along Alaska's north coast and what is now the Arctic National Wildlife Refuge (ANWR). On the North Slope of the Brooks Range, he pioneered research in ground ice (permafrost), observed birds, and collected wildlife specimens. His groundbreaking work still informs scientists and scholars.