Carl O. Sauer (born Dec. 24, 1889, Warrenton, Mo., U.S.—died July 18, 1975, Berkeley, Calif.) was an American geographer who was an authority on desert studies, tropical areas, the human geography of American Indians, and agriculture and native crops of the New World.
He obtained his Ph.D. (1915) at the University of Chicago, then taught at the University of Michigan (1915–23) before serving as chairman of the department of geography (1923–54) at the University of California, Berkeley. For Sauer, geography was inseparable from human history inasmuch as the Earth, its resources, and its environment are profoundly affected by humanity. He thus found it quite natural to delve into anthropology, archaeology, and sociology as extensions of his geographic studies. In his writings Sauer expressed a wide variety of views, including the contention that Irish monks visited America long before Leif Eriksson and that the New World was widely settled some 40,000 years ago.