The further east you go, and the farther off the beaten road the better. Pick some small towns and ask the locals if anyone around is interested. I've shot on a farmers land for several years, only stipulation was "don't shoot the cows"... I think prarie dogs are like weeds, the more you kill, the more you get... ha.

some towns you might try, Akron, Wray, Holyoke, Yuma, Strausburg, Stratton, Burlington... all north and east (maybe a little south on a couple of them) Lots of dogs around Kit Carson where I shot lots, but all private land, some farmers not open to the shooting. (no other reason but for shooting themselves usually)

kc.