Gephart, John S. (J.S.)
He appears in the 1923 and 1925 Chandler (Arizona)  City Directories  as being an engineer. He and Elsie R. Gephart lived on California St.
The 1931 and 1932 directories said J. S. Gephard lived on Route 1.
(J. F. Gephart appears in the 1932 Phoenix Telephone Directory, Chandler section, as living on a ranch, with the phone number 75-J2. )
(He could be same as or related to Gerhard.)