Rich Moore, 71, vanished with his dog on 19 August after planning to summit Blackhead Peak, a mountain-top about 20 miles east of Pagosa Springs where Mr Moore lived.
His body was found on 30 October by a hunter in the Lower Blanco drainage basin, which is in a valley southeast of Blackhead Peak’s summit, the sheriff’s office said.
The 71-year-old’s white Jack Russell terrier, Finney, was also found alive next to her owner’s body.
The 14-year-old hound is thought to have stayed by its owner’s side for seven weeks.
Finney was transported to a veterinary hospital for treatment and has since been reunited with her family, officials said.
Police did not release Mr Moore’s cause of death, but added that they do not suspect any foul play.
The sheriff’s office said a search and rescue team were flown into the area by helicopter to locate and recover Mr Moore’s body on 31 October, a day after it was discovered.
His body was found 2.5 miles east of the mountain-top, Taos search rescue team member, Delinda Vanne-Brighty, said.
“We searched from just under the peak-top and directly west, searching down the mountain toward where his car was located,” she wrote in a Facebook post. “He was found 2.5 miles east of the mountain-top beneath where we were inserted [by helicopter].”
Blackhead Peak is located in the San Juan Mountains in southwestern Colorado and reaches 12,500 feet.
It is known for its challenging terrain due to its very steep trail.
The incident marks the third time a dog has been found alive next to a hiker’s body since last year.
In May 2022, a Labrador was found lying next to the body of a 74-year-old Arizona man who had died during a hike.
Meanwhile, a month before that, an emaciated dog was found alive alongside the dead body of a missing 29-year-old hiker in Los Angeles’ Griffith Park.
Family members said it appeared the dog had not left his owner’s side for two weeks.