Colorado wildfires: Derby fire doubles in size, prompts mandatory evacuations

Lauren Penington, The Denver Post on Aug 20, 2025

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DENVER — A wildfire burning in a difficult-to-access area of the White River National Forest in Eagle County more than doubled in size Tuesday, prompting closures and evacuations, fire officials said.

The Derby fire was last mapped at 245 acres Tuesday night, up from 100 acres earlier that day. Emergency officials said there was “significant fire growth” overnight, but a new acreage estimate was not available Wednesday.

The still-growing wildfire is one of several burning on Colorado’s Western Slope.

Five wildfires — the Lee, Elk, Derby, Stoner Mesa and Crosho fires — have together consumed more than 163,000 acres, or about 255 square miles, in western Colorado.

The Lee fire burning in Rio Blanco County is Colorado’s fifth-largest wildfire on record and is only five acres away from taking the fourth-place position, according to the state’s Division of Fire Prevention and Control.

Lee and Elk fires near Meeker

The drought-fueled Lee fire burning near Meeker in Rio Blanco County has seen minimal growth in the past few days as fire crews steadily increase containment.

At 137,755 acres, the Lee fire is the fifth-largest wildfire in Colorado on record, according to the state’s Division of Fire Prevention and Control.. It’s also five acres away from surpassing the fourth largest — the Hayman fire that consumed 137,760 acres in 2002.

The Lee fire started seeing containment jumps on Saturday, after rainy weather helped firefighters gain control of the nearby 14,518-acre Elk fire. As of Wednesday morning, the Lee fire was 68% contained.

Incident commander Brent Olson said Tuesday that “conditions have subsided” on both fires.

“We are now focused on those few remaining areas of heat and closing those last remaining areas of open perimeter and helping set the stage for recovery,” Olson said.

The two wildfires have together consumed hundreds of square miles and destroyed five homes and 14 outbuildings.

Hot, dry and windy conditions — combined with steep terrain — have made fighting these fires difficult, officials said in a Tuesday night update. Forecasters expect moisture to return to the region starting Wednesday and to increase through the weekend.

The wildfire burn areas are closed to the public, and multiple zones on the Lee fire’s southern edge remain under mandatory evacuation orders. Pre-evacuation orders remain active around the Lee fire, fire officials said.

Derby fire in Eagle County

Mandatory evacuation orders were issued Tuesday for a new wildfire burning in the “remote, rugged terrain” of White River National Forest, according to the U.S. Forest Service.

The Derby fire was discovered about 15 miles from Dotsero in Eagle County late Sunday morning, forest officials said.

It was burning on 250 acres as of Tuesday night, up from 100 acres earlier in the evening, and growing, fire officials said. The flames became more active throughout the day as temperatures rose.

Residents of Sweetwater Road and areas along Colorado River Road from Sweetwater to Red Dirt Creek must evacuate the area by noon Wednesday, emergency officials said. Derby Mesa Loop remains on pre-evacuation orders.

An evacuation center with staff and resources opened Wednesday morning in Dotsero at Two Rivers Community Center, 80 Lake Shore Drive.

The U.S. Forest Service also closed parts of the White River National Forest in Eagle and Garfield counties. The closure runs from Sweetwater Lake to the north, east along the forest boundary to Derby Loop Road, northwest along Middle Derby Creek to Island Lakes and south along Island Lakes, W Mountain, Turret-Crescent and Turret Creek trails.

Fire officials believe the wildfire was started by lightning.

Stoner Mesa fire, near Dolores

A wildfire burning in the San Juan National Forest in western Colorado has consumed more than 9,000 acres with minimal containment.

The lightning-sparked Stoner Mesa fire is burning on 9,006 acres in Dolores County, according to a Tuesday night update. At that time, the fire was 10% contained.

The nearby town of Rico remains on pre-evacuation status, and parts of the national forest are closed to the public because of the fire. New pre-evacuation orders were issued Monday night from the edge of Dolores County to the Navajo Trailhead, according to the county’s emergency management team.

Crosho fire near Yampa

The 2,067-acre Crosho fire burning on the border of Rio Blanco and Routt counties west of Yampa is 22% contained, fire officials said Tuesday night.

Evacuation orders for the wildfire were lifted Monday. The fire threatened more than 200 structures, but none have been destroyed, fire officials said.

Pre-evacuation orders remain in place for multiple areas around the fire, and county roads in those areas remain closed to non-residents.

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