Tree falling on power line sparked Aspen Acres fire, report says

An aspen tree falling on energized power lines ignited Colorado’s seventh-largest wildfire on record, which burned more than 300 homes in southern Colorado this summer, state investigators concluded in a report released Tuesday.

The Aspen Acres fire started shortly before it was reported at about 5:39 a.m. June 29, about 200 feet west of Colorado 165 at mile marker 17 in Custer County, according to a 46-page report from the Colorado Division of Fire Prevention and Control. 

Strong winds uprooted the tree, causing it to fall onto power lines that hung about 3 feet above the ground. The area was covered with grass, brush and trees. Pushed by strong wind gusts, flames immediately spread west up a hill and south, before moving east, crossing Colorado 165 and west, northwest, the report said. 

“The wind was a contributing factor in the rapid spread of the fire,” they wrote in the report. 

One resident told investigators the lights flickered on and off in his home at about 5:30 a.m. the day the fire started and that he smelled smoke outside his home, south of the Aspen Acres Campground.

Investigators found charring and burn marks on the aspen tree trunk found at the origin area, where the tree had touched the hot and neutral conductors, the report said. The conductors had arcing, melting and charring. 

A separate area, near Silvercliffe Drive in Rye was also investigated as the possible origin of the Aspen Acres fire, but investigators determined the fire did not start there, according to the report. 

The fire ignited after a winter of record-low snowfall and extreme drought. With little rain falling through the summer, hundreds of firefighters and other personnel from across the country helped battle the flames.

Dry conditions persisted through the summer as the fire scorched more than 102,000 acres across Pueblo, Custer, Fremont and Huerfano counties. At least 850 structures were destroyed in Pueblo and Custer counties, according to the Alaska Complex Incident Management Team, which was one of several teams that helped manage the fire.

No one was killed or injured by the fire, state investigators said in the report. 

As of Tuesday, the Aspen Acres fire was 82% contained and is burning in remote areas, according to Inciweb, a federal database that tracks fires across the country. 

Monsoonal rains in August helped firefighters in some areas but also triggered catastrophic flooding and mudslides in Beulah, where an 80-year-old man was killed.

At least five lawsuits have been filed by fire survivors accusing San Isabel Electric Association, a rural electric cooperative, of igniting the fire. Some allege the cooperative failed to adequately clear vegetation around its power lines despite knowing the area faced a high fire risk.

Investigators wrote that they ruled out lightning, smoking materials and arson as possible causes. 

This is a developing story that will be updated.