Corson County is a county located in the U.S. state of South Dakota. As of 2000, the population was 4,181. Its county seat is McIntosh. It was named for Dighton Corson, a native of Maine, who came to the Black Hills in 1876, and in 1877 began practicing law at Deadwood. He was one of the first attorneys for the Homestake Mine. Elected to the South Dakota Supreme Court in 1889, he served until he retired in 1913.