Like Jack said...we have Richardson ground squirrels around here, but just east have some Prairie dogs. The PD's are a bit harder to get close to....the ground squirrels are pretty easy. Patience and a lot of arrows (think back quiver full) and you will get a lot of shooting...it's fun! I have killed hundreds. They do carry fleas that can carry plaque (referred to as sylvatic plaque in rodents I think - but it's basically the same). I just don't touch the buggers. Many times you will have to step on them to remove your arrow. Earlier season - they start coming out whenever the weather begins to warm - might be a better time to - less fleas...I don't know. There will be less "babies" but still it can be a target rich time. It's some fun sneaking up and shooting at them popping their heads from a hole in the snow...
Plague cases happen, but usually from other animals that contracted it from the ground squirrels. The ones I am aware of were antelope hunters who got it while cleaning their game...we still hunt antelope. Just be aware. You have a greater chance of contracting Hanta virus out here stomping around old barns, sheds, or even wood piles, than in getting plague. And for that matter of dying from it as well.
Both my boys learned to shoot and stalk on ground squirrels. Have fun.