neweboarhunter There is lots of public land to shoot prairie dogs on in Montana. Just pick up a map & find some public land in the eastern part of the state.
Before you even plan your trip call the Montana Fish Wildlife & Parks office in Miles City. They are the Region 7-Headquaters. Sorry I do not have there number handy or I would post it. They can tell you when the prairie dog season is open & closed.
Have fun,