Air quality advisories continued for Routt County and surrounding areas Thursday as the Morgan Creek fire, burning 15 miles outside Steamboat Springs, grew.

The 4,297-acre blaze has increased by nearly 1,000 acres since Sunday when crews flew over for an aerial mapping of the fire, InciWeb, a fire information system, reported.

Firefighters saw slower growth, and lessened smoke and flames Wednesday thanks to a blip of rain, according to the site Thursday brought stronger winds with gusts up to 20 mph, but humidity stayed between 16 and 21%, InciWeb reported.

About 300 firefighters battled the flames along with seven helicopters, InciWeb said.

Four of the helicopters were type 1, meaning they could transport about 15 firefighters and hold up to 700 gallons of water, according to the National Interagency Fire Center web site. The other three helicopters were type 3, which could carry four to five people and hold up to 180 gallons of water.

Voluntary pre-evacuation notices remained for some residents just west and northwest of the wildfire. No mandatory evacuations were issued as of Thursday afternoon.

The blaze prompted the U.S. Forest Service’s Routt unit to close a section of the Continental Divide Trail and trails, roads, and campgrounds throughout the Seedhouse corridor north of Steamboat Springs. Several forest roads also closed around the fire, InciWeb reported.

Officials urged hikers, bikers and other people touring the area to avoid closed sections.

The fire was first reported in the afternoon of July 9, just south of the Hinman Park Campground, while Routt County was under Stage I fire restrictions. Officials have said they do not know the cause of the Morgan Creek fire.

Several other fires continued to burn around Colorado Thursday but they had significant containment of at least 50% or more, officials have reported. Large fires burning in the Pacific Northwest contributed to the smoky conditions across Colorado in the past week.

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