The 39-year-old, who has not yet been identified, was found dead in an area north of Durango on Friday.
A black bear and two young bears were located nearby and euthanised.
Colorado Parks and Wildlife Service (CPW) confirmed human remains were found in the digestive systems of two bears.
Fatal bear attacks in Colorado are said to be extremely rare.
The woman's boyfriend raised the alarm after he came home to find the two dogs outside his apartment but no sign of his partner.
He found her mauled body off a highway later on Friday evening and called emergency services.
A team from the US Department of Agriculture located a female black bear with two yearlings (young bears between one and two years old) nearby. The animals were euthanised and on inspection, experts found human remains inside the stomachs of the female bear and one of the young bears.
Bears prefer to avoid humans but they can attack for a number of reasons, like when a person encounters a mother with her cubs, if a bear is defending its food, or when one is surprised or startled.
"Euthanising wildlife is never an action our officers take lightly, but we have an obligation to prevent additional avoidable harm," CPW Director Dan Prenzlow said.