EVERGREEN, Colo. (AP) -- Carrie Ann Warner has repeatedly called authorities about the stalker that has peered into her son's bedroom window at night, killed the family cat and even chased the family into their home in the wooded hills west of Denver.
The mountain lion has eluded wildlife officers perched on the porch with shotguns, traps baited with roadkill and even a motion-detection camera fastened to a pine tree.
Six-year-old Schylure told his parents the lion stared into his room "like it was mad at me."
"We're living in this vale of fear," said Carrie Ann Warner, whose family has built a steel enclosure around their back porch. "I've reached my wit's end. I don't know what to do."
Reports of mountain lions roaming neighborhoods and devouring family pets have cropped up from suburban Denver to Fort Collins, one of the most heavily populated stretches in the Rockies. In April, a lion attacked and broke the jaw of a 7-year-old boy on a trail in Boulder before it was chased off.
The following month, witnesses said a mountain lion walked into a Boulder home, ate a pet cat and the cat's food before being captured. And a man shot and killed a 130-pound mountain lion that attacked his dog in May outside the family's home near Buckhorn Canyon in the Arapahoe National Forest.
The number of human-lion encounters nationwide has increased from about two each year in the 1970s to between six and 10, said Paul Beier, a conservation biology professor at Northern Arizona University.
Still, mountain lion fatalities are rare _ only 17 nationwide since 1890. The last fatal attack is believed to be in January 2004, when a lion killed a bicyclist in an Orange County, Calif., park.
A 2003 book by David Baron, "The Beast in the Garden: A Modern Parable of Man and Nature" suggests mountain lions may be learning to look at family pets and people as potential food.
However, wildlife experts insist that, for the most part, the animals are naturally wary of people. Ken Logan, a nationally recognized mountain lion biologist, said science doesn't support the premise that lions are starting to view humans as dinner.
There are an estimated 3,000 to 7,000 mountain lions in Colorado. Hunting, development and other activities wiped them out in most of the East and Midwest, though most experts agree they are gradually moving east, prompting North Dakota and South Dakota to start hunting seasons.
Wildlife officers are trying to educate people about how to get along with the big cats as development pushes farther into the canyons and pine-studded hills the animals once had to themselves.
"These are intelligent animals," Logan said. "They can learn to live around humans."
But some Colorado residents say they're living in fear of the mountain lions, which can weigh as much as 180 pounds.
Tracey English no longer allows her teenage son to jog by himself in a nearby open space and her dog stays inside unless it's being walked on a leash. Last month a mountain lion was captured in a trap in her backyard.
"I don't feel like we're living in a natural wilderness. Nothing about it is natural," English said. "I believe the lions need to be managed."
Jon Silver says he has caught rare glimpses of mountain lions in the nearly 30 years he has lived west of Boulder, and warns the people living on his rental properties.
"It's just a matter of adapting to your surroundings," Silver said. "If I'm in Manhattan and it's 11 o'clock at night, maybe I wouldn't be walking down streets that weren't well lit."
For Silver, adaptation has meant devising a special dog run. His wife's German shepherd puppy, Me Too, goes outside by running through a doggie door into the garage, where it enters a door on the floor, scampers through a 40-foot underground tunnel, complete with a light triggered by a sensor, and bursts into a 24-foot-long chain-link cage.
The door over the tunnel closes when the garage door opens so the Silvers can drive cars in with no problem.
"I want to live with wildlife. It's their territory," Diana Silver said. "But I also want to protect my dog."