Born Mary Anne Reimann in Shelbyville, Indiana,[1] Richey was in the United States Army, Women's Army Service Pilots during World War II, from 1943 to 1945.
She was an Assistant United States Attorney of the District of Arizona in Tucson from 1954 to 1960.
She was a Judge of the Superior Court of Arizona in Pima County from 1964 to 1976.
[2] Richey was nominated by President Gerald Ford on June 2, 1976, to a seat on the United States District Court for the District of Arizona vacated by Judge James Augustine Walsh.
She was confirmed by the United States Senate on June 16, 1976, and received her commission the same day.