No matter what you did, you could never bring back things like Mammoths, mastodons, glyptodons, megatherium, saber-toothed cats, etc. Those animals were completely wiped out by the advance of humans who crossed the Bering land bridge and spread across two untouched continents killing off a huge percentage of the large mammals they encountered.
But there are the surviving Pleistocene animals who can (and should) be restored to their former ranges.
Already the elk has been brought east again. True, the eastern elk is actually extinct, but the variety that now roams the forests in the Midwest, in Pennsylvania, (and now in North Carolina) is so close as to be almost indistinguishable from the type eradicated by the advancing Europeans. It would be nice to see them living in all of the eastern forests again.
A bull elk that I photographed just a few weeks ago in the Great Smoky Mountains National Park.
Another creature that could be returned, but which probably will not be (as long as humans can be brought to bear against them) is the American bison, commonly called the "buffalo". These creatures once lived from coast to coast and inhabited every land type except for the wettest swamps and the deepest, driest deserts. And, once more, the type that once lived here in the east is completely extinct. The last woodland buffaloes in the east were hunted down and eaten in Kentucky in the late 1700s. Since then, there have been no bison here in the east.
But bison could be restored to eastern forests. There are similar animals who could easily adapt to our forests and once more inhabit them. The main barrier to their restoration is, once more, human opposition. Bison are very big animals (largest native land mammals in North America) and can sometimes be quite aggressive. Convincing easterners that our wild lands would be better off with bison than without them would be a tough sell. I think the nearest free-ranging bison to our eastern lands are in Oklahoma where the locals have learned to tread softly and understand the risks.
An almost free-ranging bison herd at Land Between the Lakes in Kentucky/Tennessee. (Not true free-ranging since the borders of the area are policed against their movements.)
In the northeast, one animal largely missing from the scenery is the woodland caribou. There are still some extant in Canada, and I've heard rumors that some have been seen in Maine forest just south of the Canadian border, but those might merely be cases of wishful thinking. However, the animals are not extinct and could be returned to the forests of Maine, New Hampshire, and Vermont if only some effort were made to protect enough habitat to allow them to find the area once again attractive.
An eastern woodland caribou in Newfoundland.
A huge piece of the ecological puzzle that could be restored are our extant predators. And chief among these are the Grey wolf and the mountain lion. Other than some brief and singular appearances from time to time, there really are no mountain lions remaining in the east outside of the small pocket of the animals that have survived in Florida. Allowing the mountain lion to return to the east and exist here unmolested would be a relatively easy thing to do. The hard thing would be to control the mad hysteria of the eastern humans who have grown accustomed to living in a world without such large feline predators.
The true eastern cougar is extinct. But western types could flow right into the old ecological niche with ease.
And, of course, wolves are the bane of the corporate greedheads who rule us all. To sustain healthy wolf populations you need lots of true wilderness, and true wilderness means that the lands encompassed as such cannot be exploited by mines, by drilling, by timbering, by urban sprawl. The filth who profit from the degradation of our lands always find it easy to loose their mindless rabid tools, the hunters and gun-humpers and ATV fans who scream like the spoiled brats they are when anyone champions the aim of returning the Timber wolf to its native range.
A Great Lakes timber wolf. It's only a short distance from the Midwest to the East. Let's allow them to return home.
Coyotes have been able to move back into former Timber wolf range and partially fill the ecological niche that the wolf filled. But coyotes aren't wolves and can't really do the same jobs that wolves did. And that job was to curb the growth of the vast herds of whitetail deer that fill the east from the deepest forests to the very edges of our urban areas. Many forests in the east cannot grow properly because of the sheer numbers of hungry deer who browse constantly and prevent the growth of native trees and plants. Deer are largely uncontrolled and their numbers threaten our native ecosystems here in the east. What is needed is the return of the wolf and the mountain lion.
I would love to be able to go hiking and backpacking and trekking in a restored eastern forest habitat that included woodland bison, elk, wolf, and mountain lion. Maybe one day this will happen. My suspicion is that it could happen, but only in the absence of humans. The humans will definitely go away at some point. When that occurs, I have to hope that our elderly Pleistocene friends will have survived to once again roam where they have been excluded for far too long.
For now, if you want to experience scenes of Pleistocene flora and fauna, there are precious few places where this can happen. I was lucky enough to go driving and trekking in Yellowstone National Park last year. There, the Pleistocene megafauna are still around--what remains of it, at any rate. You can stand on hilltops and see bison and bighorn sheep and elk and mule deer and pronghorns and wolves and grizzly bears and (if you're lucky) mountain lions and lynx. There are also great opportunities to see what's left of our Pleistocene pals in a number of places in Alaska, Montana, Idaho, and in several of the Canadian provinces. Hell...there are places where the wolverine still roams. But here in the eastern USA, such things are only the dreams of those of us who wish to see even a portion of the biological health restored to our lands.
RESTORE, a movement to create a new National Park in Maine, restoring the Pleistocene flora and fauna as closely as possible. Of course corporations and gun-humpers and four-wheel/snowmobile fuckheads will fight to ensure that it never happens.