Evacuations mandated as Colorado wildfires explode in size, blanketing area with smoke

 A wildfire raging in the foothills of Fort Collins, Colorado has burned more than 318 square miles to become the largest in state history, triggering evacuations and blanketing the area with choking smoke.

The blazes have burned the second-most acreage since 2000 and included the state's two largest on record. One of Colorado’s smaller fires exploded late Wednesday from 30 square miles to 196 square miles and closed Rocky Mountain National Park.

And there’s no end in sight for one of Colorado’s worst wildfire seasons on record.

“We know that there are structures lost,” said Grand County Sheriff Brett Schroetlin in a news conference Thursday.

His statement referred to the East Troublesome fire that continues to burn near Grimes Peak on the Arapaho National Forest. The U.S. Forest Service said it’s only 5% contained and has burned more than 125,000 acres, and authorities said the fire is spreading at a rapid pace. In a Facebook post Wednesday, Schroetlin said 6,000 acres per hour were burning.

A mandatory evacuation was in effect in some areas near the fire. Other areas remained on high alert.

Colorado's fires haven't destroyed as many homes as the headline-grabbing wildfires in California and the Pacific Northwest the past few months, but they have worn down residents already weary from the coronavirus pandemic.

While the season began with limited property destruction, two fires erupted last weekend in Boulder that burned 26 homes.

In parts of Colorado, the sky has been gray, the sun hazy and the odor of a burning campfire persistent for much of September and October. The Denver metro area and eastern Plains have been blanketed with smoke from fires not only in Colorado but blown in from Utah, California and Wyoming.

Glen Akins said the smoke has gotten thick and dark enough that streetlights have turned on during the day where he lives in the northern Colorado city of Fort Collins.

The air quality has gotten bad enough in some areas that Gov. Jared Polis has encouraged people to stay indoors to avoid the health effects of smoke that are compounded by the coronavirus.

Firefighters continue to battle other wildfires in the state. The U.S. Forest Service said the Cameron Peak Fire covered nearly 207,000 acres and was 55% contained as of Thursday. The Calwood Fire was 24% contained, covering nearly 10,000 acres.

All three sites are located in the Arapaho and Roosevelt National forests.

More than 700 square miles of land has burned in Colorado at a cost of more than $215 million — with the numbers still rising, according to Larry Helmerick, fire information coordinator for the Rocky Mountain Area Coordination Center.

The U.S. Forest Service said the causes of the three fires are unknown and remain under investigation.

Scientists say climate change is responsible for more intense and frequent extreme events such as storms, droughts, flooding and wildfires.

Storyful and the Associated Press contributed to this report.