Buffalo County was created in 1864 and organized in 1871. It was among the first counties to receive a name and place on the map of the old Territory of Dakota, and was, at one time, the largest county within the limits of the present State of South Dakota. In 1868 it included the present counties of Buffalo, Brule, Jerauld, Aurora, Sanborn, Davison, Hanson, Miner, McCook and part of Lake. Governor Pierce appointed county commissioners in October of 1884 and Duncan was designated as the temporary county seat. Several county seat propositions were considered at a meeting in January 1885, and Gann Valley was declared the county seat. As was the case in many counties, a fight to move the county seat ensued. The site for the new county seat was known as Buffalo Center. After the protests and legal battles were over, Gann Valley was again named the county seat in April of 1888.
