Human remains were found in the stomachs of two of the three black bears euthanized in Colorado after a woman was found dead in a suspected bear attack Friday night, wildlife officials said.

The body of the 39-year-old woman was discovered in Trimble, north of Durango, after her boyfriend returned home and found her two dogs outside and still leashed but no sign his girlfriend, Colorado Parks and Wildlife officials said. He found her body after searching for about an hour and then called 911.

COLORADO WOMAN FOUND DEAD NEAR HOME FROM APPARENT BEAR ATTACK, WILDLIFE OFFICIALS SAY

The CPW said wildlife officers responded and found signs of consumption on the body and an abundance of bear scat and hair at the scene.

CPW officers, La Plata County Sheriff’s deputies and dog teams investigated the area and found a black bear sow and her two cubs nearby.

A black bear sow and her two cubs were found in the area where the woman's body was discovered.

A black bear sow and her two cubs were found in the area where the woman's body was discovered. (Colorado Parks and Wildlife)

The three bears were euthanized out of an abundance of caution taken to the CPW’s health lab in Fort Collins for necropsies.

"Euthanizing wildlife is never an action our officers take lightly, but we have an obligation to prevent additional avoidable harm," said CPW Director Dan Prenzlow.

A wildlife pathologist discovered human remains in the digestive systems of the sow and one cub, officials said. The second euthanized cub had no signs of human remains in its stomach.              

The bears all appeared in good physical health, officials said, with initial findings showing no signs of disease or other abnormalities.

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"Once a bear injures or consumes humans, we will not risk the chance that this could happen to someone else," said Cory Chick, CPW Southwest Region manager. "We humanely euthanize that bear because of the severity of the incident."

Chick said that bears will return to a food source over and over and warned that a bear that loses its fear of humans is dangerous.

"And this sow was teaching its yearlings that humans were a source of food, not something to fear and avoid," he said.

An autopsy is expected to be conducted on the woman’s body Tuesday to determine the cause of death and identify the remains.