Aug 22, 2023 - Climate

Humans caused 60% of Colorado wildfires over the past 30 years

Data: Short, 2022, Spatial wildfire occurrence data for the United States; Note: Only includes fires with known origins. White areas had no reported fires; Map: Erin Davis/Axios Visuals

People caused the majority of the nearly 69,000 wildfires that raged across Colorado over the past three decades.

Why it matters: With climate change increasing wildfire risk throughout the West and smoke now regularly blanketing cities like Denver, changing human behavior could make a significant difference against a rising threat.

By the numbers: From 1992 to 2020, about 60% of Colorado wildfires were caused by human activity, while lightning accounted for the rest, a U.S. Forest Service analysis found.

  • The top three human activities causing the flames in the state are recreation and ceremony (12.4%), sparks from equipment, like cars, chainsaws and ATVs (5.7%), and smoking (5.4%).

The latest: Numerous wildfires are currently burning across western and southern Colorado, per Inciweb.

  • The largest — Little Mesa fire, about 12 miles southwest of Delta — was caused by lightning, officials say, and has torched more than 3,800 acres since starting July 31. The blaze is 30% contained as of Monday around noon.
  • Meanwhile, the Quartz Ridge fire in the rural South San Juan Wilderness has burned more than 1,500 acres. The flames are 0% contained due to fire crews' inability to access the steep terrain, and the cause remains unknown.

Flashback: The 2021 Marshall Fire — Colorado's most destructive in state history — started from two fires, both of which had human connections.

  • The first ignited at a residential property from leftover debris and embers, while the other is believed to have sparked from an Xcel Energy detached power line.
  • The fire destroyed more than 1,000 homes in Boulder County and cost $2 billion in damage.

Get more local stories in your inbox with Axios Denver.


Support local journalism by becoming a member.

Learn more

More Denver stories


Get a free daily digest of the most important news in your backyard with Axios Denver.


Support local journalism by becoming a member.

Learn more