Reason is that the American Natives» dogs intermingled with local wolf populations, thereby contributing to gene pools along the divide till the settlers and the army destroyed all the natives and their dogs in most tragic of the world events.
It's the part about states and tribal governments having the right to allow greatly expanded killing of wolves in «non-essential» populations where local officials determine that wolf packs are taking too big a share of deer and elk herds also coveted by hunters.