Hill City, is the owner of Johnson Environmental Concepts of Rapid City. She holds a B.S. in chemistry from Black Hills State University, an M.S. in chemistry from Iowa State University, and a Ph.D. in geology from South Dakota School of Mines and Technology. She currently serves on the Research & Commercialization Council. She was federally appointed to the Congressional Commission on the Advancement of Women and Minorities in Science, Engineering and Technology, and is a member of the National Research Council Committee on Women in Science & Engineering. She was a 1997 Bush Foundation Leadership Fellow and is a member of the American Chemical Society, Geochemical and Environmental Sections; South Dakota Association of Environmental Professionals; and the Environmental Assessment Association. Appointed by Governor Rounds in 2005, her current term will expire in 2017. Regent Johnson served as president of the Regents from 2011-2013.