Keel Kemper has driven a hundred miles out of his way to study tracks that the finder swore were left by a mountain lion. "Coyote," recalls the veteran wildlife biologist with the Maine Department of Inland Fisheries and Wildlife. He has called in the state crime lab to inspect pictures that the photographer insisted portrayed a mountain lion. "Bobcat," Kemper says. He has fielded dozens of reports from people who contend a mountain lion just bounded through the trees around their homes. "Statistically, the animal most often confused with a mountain lion is the white-tail deer," he remarks.

Confirmed accounts of mountain lion sightings in Maine in the past half-century can be counted on the fingers of one hand, with digits left over. Yet every year dozens, if not hundreds, of Mainers bring out the family Bible to swear that they spotted a cougar racing across the logging road in front of their car north of Greenville or slumbering in a tree in Jefferson.

Mountain lions may be the most sighted and yet least proven denizen of the Pine Tree State. They're the Bigfoots of the North Woods: furry, mysterious, dangerous, slinking through the shadows and watching from the brush. And like Bigfoot fans in the Pacific Northwest, Mainers want and believe the mountain lion to be part of their geography, even if the experts say otherwise.

"I know what I saw. It wasn't a bobcat," declares Dale Hahn, a Waldoboro contractor who took two photos of a big cat as it crossed the front yard of his house on Medomak Pond in July 2005. Wildlife biologists aren't so sure to this day, and Hahn says state officials "didn't really want to say what it was."

Kemper says he personally doesn't believe Hahn's photos show a cougar. "Either it was a mountain lion without a tail or it was a bobcat," he says. But don't expect him to start a debate about what Hahn did or didn't see.

"I've investigated mountain lion sightings for years," Kemper explains, "and I don't spend a lot of time anymore trying to disprove what people think they see. They get so excited about the thing they want to see, you just make them mad when you try to tell them otherwise."

Ken Miller wanted to believe. As one of the founders of the Cougar Network, a nationwide organization devoted to scientific study of Felis concolor, the animal known variously as mountain lion, cougar, puma, panther, catamount, and painter, Miller expected to find all sorts of proof that mountain lions lived in the hills near his home in Concord, Massachusetts, or in the North Woods of Maine.

"Then I saw the evidence people offered," he recalls. "Tracks that were obviously dogs or moose, pictures and videos of house cats and bobcats. I saw a video from western Massachusetts - we get a lot of sightings from there - that was so obviously a house cat you had to wonder what the person was thinking to look at that and see a mountain lion. There's a lot of wishful thinking out there."

Mountain lions were once endemic in Maine, but hunting and habitat destruction wiped them out by the end of the nineteenth century. The last confirmed cougar killed in Maine was shot near the Quebec border in 1938. Today there are no confirmed breeding populations east of the Mississippi River, with the exception of a small number of Florida panthers surviving in the swamps of the extreme Southeast, according to Clay Nielsen, a zoologist at the University of Southern Illinois who specializes in the species and is director of scientific research for the Cougar Network. The eastern mountain lion is on the federal endangered species list, but a review currently under way may change that if biologists conclude that the western and eastern cougars are genetically identical, as many suspect.

Mountain lions generally have tan-colored coats - reports of so-called "black panthers" can usually be traced to fishers, black cats, and even bears - and can hunt across territories of up to a thousand square miles. They range from Mexico all the way to northern Alberta and prey mostly on deer and beavers.

Wildlife experts say people often mistake smaller cats for mountain lions because they don't appreciate how large a cougar is. "We're talking about the fourth-largest cat species in the world," Miller explains. Males weigh 110 to 180 pounds, with females slightly smaller. The largest mountain lion ever captured weighed 230 pounds, Miller adds.

But are they in Maine? "The likelihood of a breeding population of mountain lions in Maine is minimal," says Nielsen, who spent several months near Clayton Lake in Maine working on lynx research two years ago and is familiar with the state. Cougars in the West are thriving, and Nielsen notes that they are spreading east into the Badlands of South Dakota and along river corridors. But Nielsen and other mountain lion experts generally agree that there are no significant mountain lion populations on this side of the Great Plains, either in eastern Canada or the U.S. Northeast.

Kemper qualifies his support of that idea by noting that mountain lion DNA has been found in the Fundy National Park in New Brunswick and at a site south of Quebec City. But he also notes that "we don't get many mountain lion sightings from Aroostook County. They're mostly in places like Damariscotta and Waldoboro and midcoast Maine." He isn't sure why, but he's been fielding a lot more reports lately. "Sightings come in spurts," he explains. "I'll go months without a call, then I'll get three or four all at once."

A common thread running through comments from people who think they've seen a mountain lion is that Inland Fisheries and Wildlife actively discourages and belittles their testimony. It's an accusation that drives Kemper to distraction. "The message I'm trying to get out is that IF&W does care," he insists. "And anyone who thinks we're afraid of acknowledging a mountain lion population because it would mean we would have to manage it as an endangered species should look at the list of endangered species we already regulate. The idea that we would know about something like that without acknowledging it is ridiculous."

Nielsen takes the CSI approach to arguments about cougars in Maine: "Show me the body," he declares. "Every place that has a breeding population of mountain lions, you get dead animals. Cars hit them, hunters shoot them, they get killed. How many dead mountain lions have shown up in Maine?"

Well . . . none. But that doesn't mean they aren't here. Ask Rosemary Townsend.

The Cape Elizabeth resident is the source of one of the two confirmed sightings of a mountain lion in Maine in recent years. In March of 1995 she was walking in a nature preserve near her home when she spotted a tan-colored animal near a small pond.

"When I first saw it, I thought it was a yellow Lab," she recalls. "Then it came out of the woods and lifted its head, and I realized it was a cat. A big cat."

Townsend slowly backed away and left the area. She recalls that the cougar looked sleek and well fed. "There were tons of deer in this place, so he was probably eating well," she says.

At the urging of her family, she called authorities the next day. Inland Fisheries and Wildlife specialists searched the area and found tracks and hair that were consistent with a mountain lion. "They said it was mostly likely a pet someone had released because it got too big for them," she explains. The animal has never been seen since.

Inland Fisheries and Wildlife has issued seven permits in Maine allowing people to keep mountain lions as pets. But Kemper suspects they only hint at the true numbers. "There are a number of people who own mountain lions without permits," he says. Among them: "Remember the guys who were into drugs and kept pit bulls to protect their operations? Well, from what we hear they are now seriously into mountain lions."

Whatever the case, Kemper says, the presence of pet cougars in Maine raises the question of whether legitimate sightings are feral escapees or truly wild animals. And even if the animal is wild, "I think it's important to point out the distinction between having a mountain lion here and there and having a breeding population," he notes. "It's not rare to have the occasional wolf wander through from Canada. Do we have a resident population? No."

Miller allows the possibility that mountain lions could eventually filter into Maine either down through Canada or along the Appalachian Mountains. "That's how coyotes came to Maine, and at first there was a lot of doubt about if they were here and what they were," he notes. "If cougars aren't there now, they probably will be at some point. Maine has plenty of prey and cover, and it's lightly populated."

"The question is distance," Nielsen adds. "Can an animal get to Maine from Canada or the Great Lakes? It's really too early to say. The closest breeding population is the Black Hills, but a dispersing cougar can travel a thousand miles."

And when it happens, if it happens, the public reaction will be interesting. There have been several cases in California and Colorado in recent years of cougars attacking and killing humans. Miller recalls an instance a couple of years ago when a police officer in the town next door to his reported seeing a mountain lion chasing a deer at 2 a.m.

"The chief of police believed him, and the next thing you knew they were putting up signs warning people about the mountain lion in the neighborhood," Miller says. "They shut down the street where it was seen. Farmhands refused to go into the fields, and the police were passing out flyers to kids on the school buses."

Miller was called in to inspect the scene. "I looked all over the place and found nothing but dog tracks," he recalls. "I think what he saw was a dog chasing a deer."

But the reaction is a major reason why no one even utters the possibility of deliberately reintroducing mountain lions anywhere in their former territory. "It would be a political nightmare," Miller notes. "People would be afraid their children would be in danger."

Kemper hopes that Mainers would react a little more sensibly. "In Maine, we're accustomed to living around and recreating with dangerous animals in the woods," he points out. "A moose will kill you if you meet one on a bad day, but that doesn't stop anyone from going to the North Woods. We have the most robust black bear population in the Lower 48, and they're not patsies. But people still go hiking along trails."

Kemper tries hard not to discount the possibility of mountain lions living in Maine. Indeed, he often sounds like he wants to see them. "I don't doubt something is going on out there," he allows. "Too many educated, articulate, sober people are coming to us and saying, 'This is what I saw.' "

Barring hard evidence, any suggestion that Maine has a resident mountain lion population remains speculation. That won't stop people from seeing them, though.

"I think people want to see a mountain lion," Nielsen muses. "It's mysterious and dangerous and exciting. It's a way of saying the wild is still out there beyond the backyard."