Mitch Miller first became involved in motorsports in 1965 in public relations and advertising roles with the Rocky Mountain Midget Racing Association. In 1966, he began announcing for the RMMRA and was then elected president of the RMMRA in 1970. He served in that position for seven years, and also served as the organization’s vice president and business manager. During that time he also served as an announcer for all RMMRA races and several USAC shows.
In 1978, Miller began the Belleville Midget Nationals, which soon became the largest midget race in the country. Miller also directed the South West Independent Midget Series from 1981-1985 and the American Independent Midget Series from 1983-1995. In 1987, Miller helped start the Chili Bowl midget race.