SD has over 5 million acres of public and private land leased. We have 3 national grasslands, walk in, state land and school lands. With all that land out there I'm sure you can find a dog town or two. http://gfp.sd.gov/hunting/areas/
You don't need to pay anyone to shoot prairie dogs. Get yourself some maps. Contact the 3 National Grasslands and ask them. Also they do close down dog shooting during a certain time of the year on the grasslands.