The East Troublesome fire, Colorado’s second-largest wildfire on record, was human-caused, the U.S. Forest Service announced Friday.

In a news release, investigators said they believe the blaze was caused by either a hunter or a backcountry camper – possibly by accident – due to the location and time of year the fire ignited. 

Investigators with U.S. Department of Agriculture and the Grand County Sheriff’s Office are working to identify whoever ignited the blaze.

The East Troublesome fire broke out on Oct. 14, 2020, as a small fire about 15 miles northeast of Kremmling. 

After firefighters battled the blaze for a week, the fire grew from 18,500 acres to 187,964 acres from Oct. 21 to Oct. 22, according to the fire incident management website.

Red-flag weather conditions mixed with dead and downed beetle-killed trees fueled the flames as they spread through Northern Colorado and torched 370 homes and 188 outbuildings.

The fire’s spread was mitigated by a storm system that dropped snow and lowered temperature in the impact zones, which helped firefighters contain the blaze. 

The fire was fully contained on Dec. 1 – 48 days after it began.