My dad (a folksinger now living in Seattle) used to play us a tune with the refrain:
"Very next day the cat came back
Thought he was a goner but the cat came back
'Cause he couldn't stay away"
Klandagi, Lord of the Forest (as the Cherokee called it) used to have a nationwide range in the United States. Reports of cats outside the shrunken WWII-era range of the Western US and Florida - in other words, members of the supposedly exterminated Eastern population - kept trickling in, and they continue up to the present day. Most are mistakes, but some are intriguing, and a few are seemingly undeniable. Ecologist Chris Bolgiano wrote from her home in Virginia that "Sometimes it seems I am the only person I know who hasn’t seen a panther.” She added in her book on the animal that, while she was very cautious in accepting cougar reports, "“I myself have seen a home video filmed in western Maryland in 1992 that showed an unmistakable cougar stepping momentarily between trees in a forest.”
In this article, the NYT examines the slow return of the cougar.
"There are increasing reports of sightings in 11 Midwestern states, as well as in Arkansas and Louisiana. A young male tripped a trail camera in the Missouri Ozarks on Feb. 2, and dogs treed one in Minnesota in March."
Actually, there's a lot more going on than that. It's not clear the Eastern cougar was ever extinct, despite the official position of the US Fish and Wildlife Service (FWS) (which oddly got around to declaring extinction only in 2011) and many state agencies. Consigned to oblivion (or to cryptozoology, which to some experts is the same thing) since 1938, the Eastern cougar just might have hung on. A wildlife biologist reported a good sighting in New Jersey in 1958. A private effort, the Eastern Puma Research Network, reports 11,000 (!) sightings since 1965. Despite the very conservative attitude of the FWS, an old agency fact sheet said evidence from the Great Smoky Mountains National Park in the 1970s indicated “there were an estimated three to six cougars living in the park.” (One wonders where these five or six cougars were supposed to have gone when the declaration of extinction came 36 years later.)
It's true that genuine cougar sightings may be of released or escaped exotic pets, as this New York fact sheet says. The FWS says it has tracked 110 sightings to cougars which were not native. A cat which left tracks in Rhode Island in 1998 foraged in a garbage can, unknown behavior for a wild cougar. A cougar killed in Tennessee in 1971 may also have been domesticated. It can be hard to tell, even with DNA, because there's not a clear distinctinction between cougar subspecies. An Eastern cougar is an Eastern cougar because it lives naturally in the East.
Tracks, hair, and droppings found in New Brunswick in 1992 were identified by wildlife officials as belonging to a cougar. A deer definitely killed by a cougar was found in New York in 1993. The FWS confirmed that droppings found in Vermont in 1994 were from a mother cougar and two kittens. A farmer in Virginia was compensated by the government in 1998 after a cougar apparently killed his goats. Most recently and famously, a wild cougar from South Dakota (according to DNA) was killed in Connecticut last year. Granted, this animal, having made a cross-country trek, didn't qualify as an Eastern cougar (maybe you'd call him a tourist?), but demonstrated again there was suitable cougar habitat in New England. To the north, the Departnment of Natural Resources in Ontario, Canada, still believes there are cougars in that province even though there have been no kills since 1884.
I'm pretty conservative on large cryptozoological land animals. I don't accept the mass of sasquatch sightings, for example, as proving sasquatch. But I think sighting evidence is more persusive when you're talking about an animal you know DID inhabit an area of interest. Given that the white-tailed deer, almost wiped out in the late 1800s, is now so abundant it's called "the long-legged rat," and the competing wolves are largely long gone, the remaining wilderness areas in the Eastern cougar's range are more than sutiable - they are pretty much cougar paradise, where the wary cats would never need to approach human dwellings and would be seen only by chance.
So I suspect that the Eastern cat has not come back... because it was never gone.