Christine Poke knows what she saw.
The mountain lion, extinct in the eastern United States as far as biologists are concerned, nonchalantly cut through her Lenox neighborhood, making a surprise appearance during her otherwise uneventful morning stroll.
"I was walking down the road here on Galway Court and it crossed right in front of me," Poke said. "It just crossed the road; it was just very happy and just padded along."
That was a year ago, and it's just one of hundreds, probably thousands, of mountain lion sightings in the Berkshires over the past decade - sightings of an animal that doesn't exist here, according to the U.S. government. There are thriving populations of mountain lions on the West Coast and throughout South America, but in 2011, the U.S. Department of Fish and Wildlife declared them officially extinct in the East, where they lived and hunted until the entirety of the native breeding population was killed off in the 1800s by zealous settlers who deemed them a threat.
The decision to classify them as extinct followed a years-long study conducted by biologists.
The last confirmed kill of a mountain lion - also known as cougars, pumas and catamounts - in Massachusetts was in 1858 on Mount Tom, near Easthampton. That specimen is still on display in a nearby wildlife center.
In the debate over the species' fate here, science is pitted against lore, with the latter bolstered in its most extreme form by deliberate hoaxes, wild conspiracy theories and vehement believers.
Caught in the middle are people such as Poke - residents who just happened across the elusive animal and now preface their sighting stories with disclaimers such as: "I'm not a crazy person, but ..."
As it turns out, it's possible for a sane, reasonable person to legitimately spot a mountain lion in the Berkshires - it's just unlikely.
Tom French, a biologist with MassWildlife, said the state agency gets hundreds of reports each year. Most, he said, turn out to be misidentification - either bobcats (much smaller), coyotes, big domestic dogs, or even house cats.
The accounts have trickled in steadily since the 1900s, when mountain lions first were assumed extinct in the Northeast.
"Some [sightings] are fairly convincing; others, who knows," French said. "The ones where there have been tangible evidence, either from photographs or otherwise - they're never mountain lions."
Except in one case.
DNA testing confirmed in 1997 that excrement found in the Quabbin Reservoir, located in the middle of the state, was from a North American mountain lion.
And more recently in Connecticut, a mountain lion was struck and killed by a car in Milford. That was in the summer of 2011.
But no one who has studied the big cats seems to think these rare confirmations are an indication that the animals have established a breeding population here. Instead, the animals are believed to be wandering strays - transients that have traveled hundreds of miles into the East in a long, misguided search for a mate.
The Connecticut mountain lion, for example, was traced to a population in the Dakotas.
"It's absolutely clear we do not have any populations of mountain lions," French said.
"I think we've had maybe a couple or a few that might have been real and gone through the state, but that's it." Robert Tougias, author of the book "Quest for the Eastern Cougar," agrees. He's also open to the idea that some sightings are of mountain lions that were kept as exotic pets and eventually escaped or were released.
"People think that if there's a track or a scat, they think that's evidence, that's proof. But if you look at all of the pieces of evidence, scattered over the decades, there's nothing that would indicate a breeding population," said Tougias, a Connecticut resident.
Christopher Spatz, president of the Eastern Cougar Foundation - an organization founded with the explicit goal of documenting the presence of the animals in the Northeast - spent thousands of hours investigating reports, but few turned out to be credible.
"We were built to find evidence. We wanted to find evidence," Spatz said in an email. "In the 13 years we've been doing this ... one confirmed piece of evidence crossed our desk prior to agency confirmation. People have sent us 13 years of bobcat and house-cat pics, and dogs and deer, that they reported as cougars. The agencies aren't lying when their investigations report misidentifications."
In contrast, Spatz last February went mountain- lion tracking for four days in Montana, where there is an established population, and said he found the animal's tracks, scats and fur " within minutes."
Many Berkshires residents, however, remain determined to believe mountain lions live here.
Pictures from a co- worker's neighbor or a friend's cousin dart around the web in emails. One such picture, supposedly taken in Richmond and forwarded to The Eagle, turned out to be from Indiana, taken by an automatic game camera set up by the state wildlife agency.
Some of the hoaxes end up in French's in-box at MassWildlife.
The worst was a photo of a "badly mounted," stuffed mountain lion placed in the woods. The most recent he remembers came from Peru, forwarded by someone who fell for a trick perpetrated by a cousin.
"He sent us real photographs of the animal looking in a porch window," French said. "And they're real. It's a great mountain lion shot. And yeah, they were first printed in a paper in Boulder [Colo].
The problem was the person who sent them believed with his heart and soul that they were in the Berkshires because his cousin swore he took them himself.
"When I showed him the pictures from Boulder, he was embarrassed, and his cousin thought it was a big joke."
Tougias said he appreciates the lore and the desire to believe the cats are making a comeback from extinction. He calls the prevalence of sightings "an interesting phenomenon."
"I think people want to believe that the lands they hunt and fish and hike can hold some mystery," he said, "so they want to believe that any animal of unknown origin that may resemble a cougar may in fact be a cougar."