Groundhogs (most people call them woodchucks these days) like well-drained soils that will hold up when they dig a den. They also love grass and clover and veggies, especially bean leaves, as we discovered in our garden.
Due to the number of folks hunting them with varmint rifles, and the prevalence of coyotes, foxes, and flying predators, woodchucks have made their homes inside of woodlines, along controlled-access highways, parks, and other places where we can't hunt/shoot.
Here in Maine, we used to hunt them in rolling terrain, using hunting rifles, for practice if we ever got to shoot at a scarce whitetail (back in the early sixties). I used a Savage 110, 30-06 with a 2.5x scope and managed to score out to 500 yards once, but averaged over 200 yards with that rig. It was a sporter and that's what we liked to carry on the several miles we walked per day.
Shooting woodchucks here isn't like prairie dogs out west. They're few and far between, since dedicated varmint rifles made it so easy to shoot them. The best way to find out where chucks may be a problem is to talk with game wardens and farmers in the area...mostly farmers.