Three people died Saturday when their single-engine plane crashed in the Sarvis Creek Wilderness Area near Rabbit Ears Pass, the Routt County Sheriff's Office reported.
Sheriff John Warner said the identities of the victims were not known. The plane's point of departure and destination have not been determined either, he said. The bodies were transported to the coroner's office.
Warner said smoke was reported in the area about 10 a.m. The Steamboat Springs Fire Department was unable to locate a fire; however, a few hours later, Forest Service officials in a helicopter spotted the 1/4-acre fire, which was sparked by the plane crash.
As the helicopter drew closer, Warner said the crew was able to see what appeared to be the wreckage of a drone on the ground. A drone is an unmanned craft controlled by radio.
At 4 p.m., it was confirmed that the aircraft was a downed plane.
The plane went down about 6.5 miles south of U.S. Highway 40 on Rabbit Ears Pass.
The crash site is near Harrison Creek about a mile south of Walton Peak, which is at 10,500 feet elevation. The area is heavily wooded and difficult to access.
The Forest Service helicopter was the only way to combat the fire. A crew of four people in the helicopter put out the fire with buckets using water from springs near Walton Peak. The fire was extinguished shortly after 8 p.m.
At about 6 p.m., when the site was determined to be safe, an eight-man team, including personnel from the coroner's office, sheriff's department and Steamboat Search and Rescue, headed to the crash site to investigate, Warner said.
Warner said the men used four-wheelers to access the area.
Steamboat Springs Airport Manager Matthew Grow said the pilot of the plane likely did not file a flight plan, because there are no overdue or missing airplanes that he is aware of. About 30 to 40 airplanes took off from the airport Saturday, he said.
The fire did not pose an immediate threat to any structures. Warner said the closest building to the fire was the Walton Peak repeater site, which was a moderate distance away.
Warner said the investigation and cleanup were called off for the night and would continue this morning.
A Piper Cherokee Saratoga went down in nearly the same location Dec. 29, 2002. Three of four people on that plane survived the crash and were rescued after eight hours, when emergency personnel made it to the site despite a driving snowstorm.
Grow said high-altitude flying can be especially difficult. The elevation, coupled with high temperatures, can make for complications. The temperature was in the 90s on Saturday.
"The hotter it is, the less performance an aircraft has," Grow said. He said the elevation makes the air less dense and the heat makes the air even thinner. A takeoff in such conditions requires more runway space, he said.
"You've got to be aware of the aircraft performance criteria," he said, "especially when you are flying in the mountains."
He said pilots should be specially trained to fly in mountainous regions. A variety of techniques should be used when maneuvering around mountains and valleys, he said.
"You don't fly right up the middle of a valley," he said. Many pilots make fatal mistakes simply because they are untrained in such conditions, he said. "Unfortunately we lose a lot of airplanes in the hills of Colorado."