I'm leaving this message as a place holder in case anyone else researching the Chicken family of South Dakota come across it. My 4th great grandfather Joseph Chicken moved to Buffalo County from Lafayette County, Wisconsin after my 3rd great grandfather Joseph Chicken Jr. died in 1882 at age 35. Joseph Chicken Sr. came with his second wife and left his adult children back home. He homesteaded land north of Gann Valley and is buried in the cemetery on the NE side of town.
I was able to visit the cemetery this summer and found his grave. There doesn't seem to be much of Gann Valley and I'm guessing it is the only non-incorporated county seat in America! Researching online shows that there aren't many records associated with Buffalo County, I presume because much of it is Indian reservation. Are there any active Buffalo County genealogists around?