Aspen Acres Fire caused by tree hitting power lines, report finds

• The utility faces at least five lawsuits alleging its equipment and failure to reduce fire risks caused the disaster.

Driving the news: Authorities initially classified the June 29 wildfire — Colorado's seventh largest — as human-caused, but they hadn't identified what sparked it until now.

An investigation traced the fire's origin to a spot 200 feet west of Highway 165, near Custer Drive in Custer County.

• High winds uprooted an aspen, pulling overhead power lines to within 3 feet of the ground, News5 reported.
• Electrical contact heated the tree's bark and nearby vegetation enough to ignite. Molten aluminum dripping from a wire may have also played a role.
• Charred bark, melted wiring and burn patterns pointed to the same location.

Between the lines: Lightning, discarded smoking materials like cigarettes, and arson were ruled out.

• Investigators also rejected a second suspected origin near Silvercliffe Drive, where another tree had been photographed leaning against power lines.

The intrigue: Eyewitness accounts from nearby residents helped confirm the findings.

What we're watching: The report's conclusions didn't assign legal liability, nor did it find the power company negligent.

• A spokesperson for San Isabel Electric declined to comment to local media about the report or pending lawsuits, saying the utility is focused on helping the community recover.

The bottom line: The fire remains active with 82% containment after torching more than 100,000 acres.