The western states is where the majority of public lands are. I think feral hogs have a harder time getting established on public land because hunters have easier access. Places that limit hunter access, such as wilderness areas, is where feral hogs are more likely to get established on public lands. In AZ, feral hogs are sparse and the wilderness areas that have them do not have much of a huntable population.
My recommendation for those who like to travel and hunt predators is to attend a Predator Masters Convention. Looks like the next convention will be in Elko, NV in Sept 2017. It is a great opportunity to meet predator hunters from all over the USA and find new places to hunt and explore.