Harry W. Crosby is an American historian and photographer. His parents moved to La Jolla in 1935. He graduated from La Jolla High School in 1944, and studied math and science at Occidental College in Los Angeles, completing a double major in pre-med and psychology. After twelve years as a teacher of secondary-level science, mostly chemistry, he took up photography, and in 1967, was hired as a photographer to illustrate the book The Call to California for the Commission of the Californias, commemorating California’s bicentennial. Following the route of the Portolá expedition of 1769 to make photos to illustrate a text derived from diaries of the trekkers, Crosby rode 600 miles on muleback on remote trails. Since then, he has continued to do primary research and to write extensively on the history and cave paintings of Baja California and the early history of Alta California.