After a summer session with Millard Sheets at UC Berkeley Leon was encouraged to study with him further at Claremont Graduate School in Southern California. Sheets said, “You are already painting the Salinas Valley. Why don’t you continue doing just what you are doing. Your Master’s Thesis can be ‘The Human Geography of the Salinas Valley.”
During the summers of 1940 through 1942 Leon was able to do this. For 3 solid months each summer he would work under Sheets and assist in teaching, while painting on location in the Claremont, Chino and Pomona region.
In those years the area still was very rural. Orange groves and farms abounded around the towns of the area and into the foothills. The Pomona Hills were one of the favorite locations.
By the end of the summer of 1942 he received his Master’s of Art Degree.