Since Missouri was mentioned, as an aside to Bopeye's scenario, the Missouri Conservation Department has acknowledged the presence of Mountain Lions in the this state. There are many documented and verified video's, sightings, tracks, and kills. Even some road killed lions in recent history. Of interest to me is two sightings of which come from the immediate area I deer hunt. A video filmed by a Conservation Agent a couple of years ago of a lion on a deer kill was taken about 1 mile from my normal yearly deer hunting area. Last year a hunter in this same general area shot a deer right at dark and wasn't able to recover it. The next morning he and another hunter went back and tracked the deer up to find with much surprise a lion had claimed the kill. They backed off and called a Conservation Agent and he went back with them. The lion was still on the kill and they got some video before the cat took off. They figured out from the sign that the cat had jumped the still alive and wounded deer, finished the kill, and claimed it. There are many more verified sightings, but those two are of particular interest to me since they occured right in my stomping grounds. A policy was set which seems that any state could adapt if they wished.
MDC officials declared there is a scattered Mountain Lion presence in Missouri. They believe this presence is mostly from juvenile and young adult lions seeking their own territory as they expand from the western states. The MDC will readily admit the entire southern half of the state is great big cat country. Mile upon mile of heavy timbered forest, brushy creeks, valley fields, lots of rugged remote country with a good deer and turkey population. A cat could travel from mid-Missouri south through northern Arkansas with little, or no, interaction with humans. There was much discussion of Mountain Lions in the last few years. Finally an official statement that even though the big cats were once native Missouri animals, there would be no modern management to reintroduce, or sustain/maintain, a population of Mountain Lions in Missouri. The idea is that the lions would not be a desirable species to have in numbers within the state. Lion, livestock, and human interaction would only cause problems for all if the population were to grow to a substantial number. So in effect, we have them, but we are not TRYING to have them or making an effort to maintain the lion population. There is no legal hunting of lions in Missouri, though it is known that at least one was illegally shot by coon hunters whose dogs treed a lion. They tried to get the hide tanned by a local taxidermist and all were fined heavily and lost hunting priveledges and some gear used in the poaching for their shifty ways. Basically MDC has adopted a hands off policy on lions. If they make it and become problematic, I guess Missouri will deal with that as the situation dictates. If they never really establish a stable population, that's probably better yet. That seems a reasonable approach to a large predator like the lion for a state like Missouri.
The state is managing the Black Bear and Feral Hog populations. No hunting of bears, much study being done, and when bears get in trouble MDC will attempt to trap and relocate problem bears. MDC has had to do so at least a dozen times, and also to kill one problem bear that would not stay relocated and out of trouble. Another has been killed by a homeowner when it attacked his dog. The homeowner was not charged in the incident and the 350 pound bear was confiscated by MDC. Another bear was illegally killed by an out of state turkey hunter who clamied he was attacked by the bear. He later admitted to shooting the bear because it was looting his camp. He was fined and lost hunting priveledges and his firearm he used to illegally kill the bear. We have a decent bear population that is growing. The bear population is described as maybe being as large as 900 animals. The wild hog population estimates vary from 3,000 to as many as 10,000. The goal for hogs is to eradicate them if possible, though nobody believes this is possible in the Ozarks. Basically it is open season on pigs.