The Thunder Basin National Grasslands have a large number of prairie dog towns. The trouble is, there is an assortment of ownership, making it somewhat confusing for people who are not very familiar with the area. In some areas, shooting prairie dogs is encouraged by land owners, but right across the fence it could be illegal due to the prairie dogs being protected.
For whatever reason, there seems to be a boom in the prairie dog population all over the northeast region of Wyoming this year. We have noticed quite a few moving onto the ranch, but I think I have been able to keep them at bay, atleast for the time being. After the antelope hunters I guide here on the ranch successfully fill their tags each year, I will usually take them down to a few spots I know where they can get in all the shooting they want. Several times, hunters have told me they enjoyed the opportunities to shoot prairie dogs as much or more than they did the pronghorn hunt.
Just as has been stated in regards to other types of hunts, unless you are hunting on private land, I would suggest you have a quality GPS with the land owner chip. I would also suggest a call to the local game wardens for their input as well. Most ranchers and private land owners want the prairie dogs gone, but due to liability issues, they can be leery of letting strangers access their property.
You are going about things in the proper way, by starting your planning early. You are much better off trying to locate a place early and getting things in place for your pending visit. It is pretty hard these days to just show up and ask for permission to shoot. By starting early though, and developing a relationship with a landowner, even if it is only by phone, you stand a better chance of successfully getting a place locked up. Do keep in mind, the months of May and June are when many of the ranchers in this region are gathering their cattle for spring branding and they may be less likely to allow access for people coming in to shoot.
If you have any specific questions I can help answer, don't hesitate to send me a pm and I will give you my number.
Tex Adams