the world, and the Moon. Professor Waters was known, too, as an outstanding mentor of graduate students, the coauthor of a leading textbook on the principles of geology, the builder of distinguished geology departments in leading universities, and, late in his career, a valued geologic consultant to federal research organizations.
Aaron Waters was born in Waterville, Washington, on May 6, 1905, the son of pioneer parents and the youngest of seven children. His early years were spent on the family homestead and wheat ranch near Waterville, on the western edge of the Columbia River Plateau in the shadow of the Cascade Mountains. He worked on the ranch during his youth and helped to run it at age 12 and 13 during the last years of World War I, when his older brothers went off to war. Following graduation from high school, Aaron entered the University of Washington, supporting himself by work in a gas station and other jobs. He began prelaw studies but later changed to geology, partly from his love of the out-of-doors but influenced especially by his college friend Richard E. Fuller, who later became both a distinguished geologist and a long-time director of the Seattle Museum of Art. Waters earned a B.Sc. in geology (cum laude) in 1927 and an M.Sc. in 1928, both from the University of Washington.
Waters continued his studies at Yale University, known for its program in geology and development of leaders in that field. He earned his Ph.D. in 1930 under the mentorship of Professor Adolph Knopf. His dissertation, “Geology of the Southern Half of the Chelan [30'] Quadrangle, Washington,” provided the basis for several outstanding papers, and had a lasting influence on the direction of his career. The eastern part of his map area overlapped the Columbia