I live in NW Montana and we have had control of our wolves for a few years now and there is no reason for them to be on the Endangered list in any state in the northern tier, they have proliferated quite well since re-introduction as well as natural migration.
I am not a wolf hater by any means, but I am a realist and they are doing quite well, a lot of the groups, say natural balance will take over and control predator and prey populations, the only problem is, they don't figure the human populations in those predator prey populations, I have a pack of 13 wolves living within a mile of my house and you have to be prudent with them, they take dogs, cats and other live stock out quite regularly in this area.
Human live stock is much easier to take than wild prey, you had an initial drop in natural prey populations because they had not lived with wolves, now that a few generations of natural prey have grown up, their surviving much better and the natural instinct is to take the easiest prey and that is human livestock and pet animals.