 Simms died in Albuquerque on April 11, 1975.He was buried at Fairview Memorial Park in Albuquerque

Simms was the son of Anne Clapton (Schluter) Simms and John F. Simms (1885-1954), who served as an associate justice of the New Mexico Supreme Court.In 1940 he married Ruth Reynolds (1915-1989), they were the parents of three sons and two daughters.