This is a difficult question to answer. If it's just prairie dogs, then try and get a portable bench with bags on it, and a folding chair. It's more fun that way. Using a bag as a rest for use on the ground can be problematic (as can the creedmore) because low vegetation will deflect your bullet. I've started using a tripod that I made from three 3/4" dowels, some nylon cord, and a bit of foam padding. At best, it's about as good as a rifle with a bipod. I think this is because there isn't much lateral or front-to-back movement with the tripod versus the bipod. I still don't like it, so I'll have to continue with experimentation.
Ideally, however, shooting off a rucksack from a prone position is about as steady a shot as you're going to make with the Contender. It's as steady as shooting from a bench. But the vegetation problem is a very significant one.
My own opinion is that the rifle is a better choice in situations like this.