Mountain lions and humans are increasingly sharing territory.
That means reports of the animals roaming neighborhoods and devouring family pets are cropping up from suburban Denver to Fort Collins.
Wildlife officers are scrambling 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.
They say mountain lion fatalities are rare -- with only 17 nationwide since 1890 -- and insist, for the most part, that the animals are naturally wary of people.
Still, the number of encounters when an unprovoked cat makes contact with a person started picking up nationwide in the 1970s.
The number of fatal lion attacks in that span has increased from about one to three or four a decade.