The Beast in the Garden Redux: Puma-Human Coexistence Along Colorado’s Front Range

By: Christopher Spatz

July 17, 2026

“The cats, emboldened and proliferating, are heralds of a new stage in the nation’s evolution, a changed relationship between man and nature that will require an attendant adjustment in cultural attitudes.” — David Baron, The Beast in the Garden

In the wake of Colorado’s tragic death-by-puma in January, the first this century, I re-read David Baron’s exhaustively researched, richly detailed, and at times exquisitely lurid The Beast in the Garden, published in 2003. Baron, a former National Public Radio science reporter, built a case that Boulder, Colorado’s late 20th-century, laissez-faire rewilding of its boho-enduro-sports neighborhoods unleashed a curse of suburban wildlife, and a plague of pumas.

Deer began to appear, munching on the residential shrubbery. The little hippie city along the Front Range foothills decided to ban hunting them. Bears, coyotes, and pumas followed, invited by Boulder’s implied Garden of Eden collective fantasy. Dave Foreman and Ed Abbey, rewilding’s cactus-bitten progenitors cheering the recovery of wild things in our midst, were prime instigators in Baron’s narrative.

Beast’s central thesis was that wildlife — especially big carnivores living near recreating humans (like grizzlies in Yellowstone) or human settlements (pumas in Boulder) — get used to us. According to wildlife tracker Jim Halfpenny, one of Beast’s protagonists, they habituate and conflict ensues. Halfpenny and Boulder County biologist Michael Sanders began documenting puma-incident escalations through the late 1980s into the early 1990s: backyard sightings, trail-side deerkills, pets gone missing or plucked from pens, a trail runner treed and her legs raked by a pair of young cats. Beast’s “Plague” chapter concluded with a puma roaming the beer-besotted evening streets of Boulder’s university district, where the cat was frantically tracked and safely tranquilized by animal control officers, who then shuttled the drugged puma back to the mountains.

Despite the documentation and pleas for help from concerned Boulder citizens, and a warning op-ed in the Denver Post by Sanders, Colorado Parks and Wildlife (CPW) reluctantly held one town hall meeting, then did nothing. No management plan or aversive conditioning response for wayward cats was developed.

On January 14, 1991, the foreseen happened, kind of. Scott Lancaster, a student athlete running the hills around his Idaho Springs high school, 20 miles down range from Boulder, went missing. A day later, a search team located his eviscerated remains. By all appearances, they had found a murder scene. Poised disquietingly close at hand — “like it was guarding the body” — a puma was flushed from the brush and quickly dispatched. The necropsy confirmed the cat, a two-and-a-half-year-old male, as Lancaster’s killer, the first such death in Colorado in a century.

Baron argued the cat was a habituated disperser from Boulder, but without a tracking collar to monitor the cat’s movement, that’s merely speculative marinade for Beast’s stew of simmering blame. From what we know about puma dispersal, the cat could have come from anywhere in Colorado. It could have come from Utah or Wyoming. It could have been reared near Idaho Springs. Methinks Baron pushed too hard pinning Lancaster’s fate on Boulder.

Beast posed important questions on carnivore coexistence at the dawn of the rewilding movement. It is likely the bestselling book on Puma concolor of all time. To this day, when a person is mauled or killed by a puma, threats of cascading incidents by habituated cats cited from The Beast in the Garden animate news reports and social media posts.

So, how “unusual” were Boulder’s pumas? 

Wildlife habituation sure seems like an obvious troublemaker. My town library here in upstate New York displays flyers on how to disinvite the bears, coyotes, and raccoons. But a 1992 paper by California puma biologist Paul Beier found no correlation between puma habituation and conflicts with humans. Baron cited Beier’s study, but he ignored the conclusion. Habituation was a part of something larger happening in the Front Range, just as it was happening to puma populations throughout the West in the last quarter of the 20th century.

The leading edge of expanding puma ranges are dispersing young adults, mostly males — like the cat that killed Scott Lancaster. Pumas aren’t raised or trained or evolved to hunt humans. But every once in a while, a young cat newly out on its own (18 months to two years old), curious or experimenting, hungry or simply reckless, decides to stalk one of us. For obvious reasons, two-thirds of the time, they hunt a child.

Once considered a creature of obligate wilderness, the 1970s to 1990s saw pumas moving out of their mountain redoubts to settle the expanding suburbs — even into city centers. Boulder didn’t create “emboldened” cats any more than Lytton, British Columbia; Arroyo Seco, New Mexico; Evaro, Montana; and a handful of random towns hosting deaths-by-puma at the tail end of the century along the borders of the cats’ self-propelled recovery.

Puma-human conflicts ticked upward during the 1990s range expansion. Then conflicts dropped. 386 incidents (29 fatal, 171 non-fatal contacts, 186 close-threatening encounters) analyzed in this 2011 study found conflicts stabilizing in the U.S. and Canada at four to six a year since 2000. British Columbia, not Colorado or California with much higher human densities, topped the conflict list. Why did conflicts sink, then plateau?

Pumas habituated alright, to avoid conflict. Normally crepuscular hunters, they shifted to hunting colonized exurbs after the lights went off. They would leave kills the moment a human voice interrupts their meal, often abandoning the site rather than returning to feed. Consequently, pumas hunt more frequently the higher the human density. They go out of their way, navigating perceived risks, using more energy, reducing their home ranges — for good reason.

Famously, pumas — and 31 other species of megafauna, including mammoths, giant sloths, dire wolves, cheetahs, and saber-toothed cats — were wiped out from North America during the late Pleistocene. Did our Clovis-spear-wielding ancestors cause or contribute to the extinction? The debate rages. Pumas recolonized north from Central America during the last 10,000 years. Their return was welcomed by Indigenous peoples who killed them for ornament, for ceremony, and for bundling arrow quivers, before European colonists arrived with hounds and guns, traps and bounties. Speaking of plagues, pumas may well have evolved to steer clear of these two-legged packs of traveling assassins hounding them for millennia.

People, especially adults, are not easy prey. Compared to deer and elk, human necks — a puma’s primary target — are in the wrong place. We fight back with our hands, or with the weapons at hand, sometimes in groups. And unlike coursing wolves, as ambush hunters, puma lungs aren’t built for prolonged struggle. Pumas are actually risk avoidant. Hunting humans is too much trouble.

Wildlife get smarter the longer they coexist with us. In turn, we, too, adapt. Wildlife agencies and the media have taught Westerners sharing puma habitat how to handle encounters: from standing your ground to making yourself big, to fighting off cats with sticks and stones. Recreationists are advised not to run-cycle-hike solo in puma country.

Animal husbandry has adapted. Walking dogs is forbidden in many California parks. Pets are brought in at night. Ranchers and hobby livestock owners are encouraged to move their animals into barns or covered enclosures every evening. Call the habituation of learning tolerance. Call it coexistence. Call it becoming neighbors.

Anomalies occur. A string of incidents started in October 2025 in Larimer County, Colorado:  a pair of hikers were surrounded, off-leash dogs were killed on hiking trails on successive days. Multiple cats were reported at several scenes, suggesting to me orphaned youngsters trying to fend for themselves. CPW sent out search teams that were unable to locate any cats. CPW posted trail warnings. On December 23, a Glen Haven dog owner shot, not a subadult, but a healthy, three-year-old male puma mauling his dog. He turned the cat’s body over to CPW. Signs warning of recent incidents were removed from nearby trailheads, though permanent notices remained.

Then, on January 1, 2026, 46-year-old Kristen Kovatch, a Fort Collins resident hiking alone on Crosier Mountain Trail near Glen Haven, was found lying on the ground with a cat standing by. The two hikers who stumbled on the corpus delicti threw stones and hazed the cat away before ministering to an unresponsive Kovatch. Dispatched to the location, CPW euthanized one cat, then located and killed another. A third puma was unsuccessfully tracked for three days. A necropsy of the two cats revealed a subadult male with DNA matching Kovatch’s on his paws. The second, a subadult female, found no trace of human DNA. Apparent siblings, both were about one-year-old and in good shape. The male’s stomach was full of deer. Based on track sizes at the scene, CPW believes the third cat was their mother. They were not orphans. The autopsy on Kristen Kovatch determined she died by asphyxiation.

Crosier Mountain: A Battle of Succession? 

On November 12, trail runner Gary Messina snapped a picture of a puma in the brush before the cat rushed him on the Crosier Mountain Trail. Messina fended the mountain lion off with a tree branch. Was this the three-year-old male killed on December 23, a different male, or one of the euthanized siblings? CPW determined the three-year-old was unrelated to the juveniles. If not related, why was he there?

The Crosier Mountain watershed would have been the domain of an older, resident tom, the father of the subadults, and several breeding females within his territory. No three-year-old interloper would be permitted there, unless the tom had been killed — road-killed, hunted, or debilitated enough to be challenged by a youngster. Big carnivore researcher Bob Wielgus determined that when resident males are lost, three dispersers will vie for his territory until one victor emerges. Remove enough resident males, and your puma-land is soon a circus run by teenagers — see Lord of the Flies. Big toms and moms rule because they are savvy. They don’t tangle with pets, livestock, or people. Puma elders keep puma society stable, ordered, low-conflict zones.

Remember British Columbia? Like big bucks, big toms make big trophies. A look at 30 years of B.C. trophy hunting found higher harvests leading to a rise in conflicts the following year and smaller skull sizes among those cats killed. British Columbia has annual bag limits of two per hunter, but there is no quota for the total number of cats, since the number of hunters is unlimited. British Columbia’s pumas are the hardest hunted cats in the U.S. and Canada. Though B.C. has the second-lowest human density of any U.S. state or Canadian province where pumas are hunted, B.C. historically has been the puma-conflict king. And Vancouver Island, a chunk of turf the size of Maryland, remains the world’s hotspot of puma-human conflicts.

Were the months of turmoil around Crosier Mountain the result of a missing mature tom — a battle of succession? Was the well-fed young male practicing, enticed, or triggered by Kristen Kovatch solo hiking? Had the pair of juveniles been honing their hunting skills on pets for several months? Was mom a lax disciplinarian? The record of events on Crosier Mountain in 2025 reads like a Bob Wielgus blueprint.

Kara Van Hoose, CPW’s media contact, told me the string of incidents was within the mean of routine puma management in a county dense with mule deer, elk, and pumas. Only Kovatch’s death was the statistical outlier. Cougar management guidelines — developed by 22 puma professionals, including the grand-old man of puma research Maurice Hornocker — instruct wildlife agencies how to handle the range of puma-human conflicts. Depending on the circumstances, cats in the Front Range may be hazed, relocated, or euthanized. Sport hunting, long promoted by wildlife agencies as a conflict deterrent and divisively challenged by many, received a Front Range management reboot in 2025. Aversive conditioning is baked into modern state puma management. It’s hard to argue that Front Range cats are “emboldened” a generation later, as Baron suggested back in 2003, by slack policy. In contrast to the Wielgus and B.C. research, Van Hoose maintains that conflicts in Colorado are higher where puma harvests are lower. Go figure.

A decade ago, armed with David Mattson’s 2011 attack paper, Bob Wielgus’ research on misbehaving teenagers, and a handful of other studies, I contacted David Baron. I asked him to consider the latest science on puma incidents and re-evaluate his habituation argument. I reminded him of Paul Beier’s conclusion. As a science reporter, would he consider issuing an update or a new foreword for The Beast in the Garden, perhaps, on puma-human conflicts? My goal: shift the public discourse, the Reddit and social media prognosticating over pending plagues of habituated pumas.

Baron said he would look at the papers, but he felt the fury of reporting following each near-miss or death was a far bigger factor inciting puma hysteria than The Beast in the Garden. He gave the same response to carnivore advocate Wendy Keefover-Ring’s peer-reviewed critique of the book. He acknowledged the stabilization of incidents since 2000, and we mused on the possible causes, including puma habituation to avoid conflict. Our cordial correspondence ended there. As far as I know, Baron never penned an update.

Puma conflicts and coexistence are piquing interest here in the northeastern U.S. Listeners of the Rewilding Earth podcast have heard that an honest-to-god puma reintroduction campaign spearheaded by Mighty Earth and back-channeled by the Cougar Research Collaborative/Panthera is underway, striving to put puma paws back on the ground in the Northeast within five years.