HURON, S.D. (AP) – A Huron couple is donating $20,000 toward a new exhibit hall on the South Dakota State Fairgrounds in Huron. Nels and Dorothy Olsen owned and operated a farm machinery and truck business in Huron for many years. They say they are supporting the state fair project because of the positive influence of 4-H on youth throughout the state. Construction has started on the 48,000-square-foot hall. It will feature 30,000 square feet of exhibit space, multiple classrooms, a large kitchen for 4-H special food competitions, year-round concessions and a performance stage. State fair officials say they have raised more than $4 million toward its goal of $4.7 million for the project.