In 1970, the race track took on a new look as the once-flat turns were banked. That year also saw the first Late Model races. Bob Widick of Carson, Iowa won the first-ever Late Model "A" feature over Varel Schmidt of Massena, Iowa. Also in 1970, the races were held on Sunday nights and the track took the name of Adams County Speedway. Through the 1970's the race night was changed several times, trying to get more cars and fans. In 1976, the Adams County Fair Board leased the track to Bun Sheridan and Lawrence Peterson. The fair board took over the races again on July 1, 1976.

The fair board ran the races until late May, 1983 when Gail Hampel took the reins. Adams County Speedway came under NASCAR sanctioning in 1984, a tradition that continues to this day.

Since 2009 ACS is operated by the Adams County Fair and Racing Association (ACFRA) and promoted by KMA Regional Radio. Nick Wetzel is KMA's point person for promoting ACS and ACFRA installed Ray Houck as track director. Houck manages track preperation, rules and race night procedures.

The Adams County Fair and Racing Association continues to make many improvements and upgrades to the track and the entire facility to accommodate the growing numbers of cars and fans. Improved lighting, sound systems, clean restrooms, additional seating and private viewing decks have been added. The rich tradition of making ACS one of the finest race facilities in the midwest is being carried on into the 21st century.