How did medieval Europeans have such specific geographic knowledge of North America, a land even their most daring adventurers had not yet discovered? In Erikson, Eskimos, and Columbus, James Robert Enterline presents new evidence that traces this knowledge to the cartographic skills of indigenous people of the high Arctic, who, he contends, provided the basis for medieval maps of large parts of North America. Drawing on an exhaustive chronological survey of pre-Columbian maps, including the controversial Yale Vinland Map, this book boldly challenges conventional accounts of Europe's discovery of the New World.