Sandford Rex McDonald was born in Wadena, Minnesota, on June 11, 1936. He graduated from Wadena High School in 1954 and the University of Minnesota with a Geology Degree in 1959. After graduating from The University of Minnesota, Sandy worked with his father in the photography business in Wadena from 1960-1978 and took over the Rex McDonald Studio until 1978. He started a professional photographic color lab in Staples, Minnesota in 1970 with two partners.