Special Olympics Iowa will receive one of the largest contributions in its history tonight in Sioux City. ShopKo Stores Incorporated will present Special Olympics Iowa with a check of more than 159-thousand dollars at the Sioux City Explorers baseball game. Sheree Olson is a spokeswoman for ShopKo, and says the company has been involved in the organization since 1994.Olson says the money is raised from an annual charitable golf outing.Olson says the company’s commitment to Special Olympics has grown over the years. She says they can’t not get involved after seeing how the events help people.ShopKo currently operates stores in Sioux City, Mason City, Fort Madison, Burlington and Dubuque.