Deuel County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 4,364 Its county seat is Clear Lake.
Clear Lake is host to one of the largest rodeos in the area. The Crystal Springs Ranch Rodeo is held the end of June each year, drawing thousands of people to the town. It is held in the nation's most natural rodeo bowl in the Coteau Hills, a native grassland prairie formed by glaciers. During the rodeo, visitors and residents alike enjoy camping, community garage and yard sales, and a parade.