[3] Castetter was an associate professor of botany at Iowa State College, before taking a position as head of the biology department at the University of New Mexico in 1928.
[1] He also served as Dean of the Graduate School starting in 1949 and the Academic Vice President of the university from 1956 until retirement in 1961.
[1] In 1930, Castetter established one of the first graduate programs for ethnobotany in the United States at the University of New Mexico.
From 1938 to 1940, he and Willis H. Bell spent autumns studying the Pima people.
[5] Castetter and Bell also studied the Tohono O'odham, Mohave, and Puebloan peoples.