After graduating from the University of Michigan in 1920, Johnson moved to New Mexico, where he hoped that the dry, warm climate would assist him in overcoming respiratory difficulties dating back to his wartime exposure to phosgene gas. For nearly 40 years, he served in multiple other positions, including head coach of the football, basketball, track and tennis teams, and an instructor of physical education.
The Albuquerque Tribune later wrote: "For year after year Roy Johnson was the entire athletic coaching staff at the University. He coached football, basketball, track and tennis in addition to carrying a full teaching load." He oversaw construction of
Carlisle Gymnasium in 1928 and
Zimmerman Field in 1938, the first football stadium at UNM. Johnson was the head football coach at the University of New Mexico from 1920 to 1930, compiling a record of 41–32–6. His 1927 team went 8–0–1, surrendering just 28 points. In 1929, he became the first football coach to have his team fly by airplane, for a game with
Occidental College at the
Rose Bowl, the first night game played by the Lobos. During the early 1930s, he became an innovator in the use of arc lights to allow night games at UNM. Basketball had been a varsity sport at UNM since 1899, but the team played only sporadic games. Beginning in 1922, Johnson established a regular schedule of games against other New Mexico colleges and the University of Arizona, and further regional schools were soon added. From 1924 to 1934, his teams compiled an impressive record of 104–38 (). Overall, in 18 years as the school's basketball coach, he compiled a record of 165–146 (). His win total stood as the school record for over thirty years and is currently third on its all-time list. For his many contributions, Johnson has been called the "architect of institutional sport and physical education in the American Southwest with particular application to The University of New Mexico." In 1957, the University of New Mexico regents voted to name the university's new gymnasium the
Johnson Gymnasium in his honor.
Sports Illustrated reported on the naming of the gymnasium as follows:Not often has a coach received so unique an honor as has Roy Johnson. While still a member of the faculty at the University of New Mexico he has had a modern, $2.5 million gymnasium and swimming pool named after him. But New Mexico's regard for Roy Johnson had been building up since 1920... The athletic program Coach Johnson built with Swedish determination has won him the admiration and affection of his students and co-workers and the nickname Ironhead. ==Family and later years==