Just spent the last two days shooting pds on the eastern plains of CO. Forget public lands, shoot the private stuff. I have never been turned down for permission to shoot them and have been more than welcome to come back.
Prairie dogs like short vegetation, minimal water and often extend their colonies out into winter wheat and stubble fields.
Most of the fields I shoot start out by giving me 100-200 yd. shots and by the time I am moving on they are out at 350 plus and far fewer of them.