In 1956, Deitz was hired by Minneapolis Marshall High School as an assistant football coach, wrestling coach, and track and field coach.[5][3] He was promoted to head football coach in 1958, after the resignation of Norm Kragseth.[5] He was named Minneapolis City Coach of the Year in 1961.[3]
On April 12, 1962, Deitz resigned from Minneapolis Marshall to accept a position as head football coach at White Bear Lake High School.[5] "Marshall's enrollment is down and it will be down more by next fall. I just feel in the long run I can do better coaching at a school like White Bear," he said.[5] Deitz ended up coaching eight seasons at White Bear Lake, compiling an overall record of 50–18–4.[4] His final game with the team was the 1969 Suburban Conference football championship game, a 25–20 win over Kellogg High School.[6][7]
In January 1970, Deitz, one of 30 applicants, was chosen to be the next head football coach at the University of St. Thomas.[4] In his first year, the St. Thomas Tommies compiled a record of 1–9.[8] They improved to 3–7 in 1971, 6–4 in 1972, and by his fourth season the Tommies went 9–1 for their first conference championship since 1956.[8][9] For this, he was named the 1973 Minnesota Intercollegiate Athletic Conference (MIAC) Coach of the Year.[3] In the subsequent years, St. Thomas compiled records of 5–4 (1974), 3–6 (1975), 7–3 (1976), 4–5–1 (1977), and 5–4 (1978).[8] In 1979, he was awarded for the second time MIAC Coach of the Year, after stunning 7–1 St. John's in the season finale, 30–0, to force a four-way tie for the conference championship between St. Thomas, St. John's, Concordia, and St. Olaf.[3][8]
Deitz later stated that the 1979 season "was probably the most frustrating but also most rewarding" in his career as a coach.[3] The Tommies started the season dealing with several starters who decided not to return, multiple injuries, and one player's death.[3] They started the season 1–2, but had a 4–0 home record and closed the year with four consecutive wins.[3] "We lacked depth, yet we had some freshmen that came through for us," Deitz said.[3] Among the players on the roster that year was wide receiverJim Gustafson, who caught the game-winning touchdown pass against Concordia and later made it to the National Football League (NFL).[3]
Following the 1980 season, in which the Tommies went 3–6–1, Deitz resigned.[10][8] His career record at the school was 52–52–2.[10] "I've been thinking about giving up football for some time," he said.[10] "It's time I turned over the job to somebody else. I'd like to start spending more time with my wife and family."[10]
While at St. Thomas, Deitz coached each of his three sons: Dan, a defensive back; Doug, a quarterback; and Dave, a center.[11] Doug Deitz was later inducted into the St. Thomas Athletic Hall of Fame.[3]
Later life and death
Deitz later served as a member of the St. Thomas physical education faculty.[10] From 1981 to 1984, he served as a member of the White Bear Lake school board.[3] He was inducted into the White Bear Lake High Athletic Hall of Fame and the Minnesota Old Timers Football Coaches Association Hall of Fame.[3]
Deitz died on August 22, 2018, at the age of 87.[3][1]
