Authorities began weighing charges Monday against the owners of the dogs.
Jennifer Brooke, 40, was killed early Sunday when she went to a barn to care for her horses, officials said. A friend, Bjorn Osmunsen, 24, was attacked when he went to look for her.
"It's a gruesome thing; it's kind of hard to deal with," Elbert County Undersheriff James Underwood said of Brooke's injuries. "Even the fire department and the rescue personnel were having a hard time dealing with some of it."
One dog had allegedly mauled a neighbor earlier this year, and officials said the dogs were well known in the rolling ranch land near Kiowa, southeast of Denver.
"The people in the area had their own sort of emergency phone network to warn each other if the dogs were loose before they would go out," Rattlesnake Fire District Chief Dale Goetz said.
After fatally mauling Brooke, the dogs moved on to a nearby home and attacked Lynn Baker when he stepped outside.
"One was leaping for my throat as one was dragging me down by my hand," Baker said.
He said he jumped into the bed of his pickup truck and screamed for family members to call authorities, and for his 16-year-old son, Cody, to grab a gun.
Cody Baker fired at the dogs with a shotgun, blinding one, knocking one down and disorienting the third. The distraction allowed his father to climb into the cab of the pickup and drive close enough to his house to scurry inside.
"I came out and shot the big one twice but it hardly slowed him down," said Baker, whose son also was attacked but was not injured.
"They were monsters. And they don't run away. They come at you, even when you are shooting at them," Baker said in a telephone interview. Cody Baker and a deputy eventually killed the dogs. Both Lynn Baker and Osmunsen were treated for their injuries and released.
The dogs' owners, one of whom was identified as Jacqueline McCuen, could face charges ranging from a misdemeanor to negligent homicide, said Mike Knight, spokesman for the district attorney.
There was no comment from McCuen; her telephone number is listed as disconnected.