Firefighters made progress toward containing one of the largest wildfires in Colorado history over the weekend, but officials said “extreme fire weather” is expected to continue Monday and throughout the week.

The Lee Fire had burned 113,378 acres in Rio Blanco County — an area that is larger than Denver County — as of Monday, according to the complex incident management team responding to the fire. That makes the wildfire the fifth largest in Colorado history.

After heading into the weekend with no containment, fire officials said the Lee Fire is now 7% contained. But on Monday, the firefighters responding to the fire encountered flame lengths over 100 feet and rates of spread over 1 mph as high winds, according to a morning update posted to InciWeb.Wildfire.gov.

“Key factors of extreme fire behavior are present and as a result, large fire growth is being observed on the Lee Fire,” the complex incident management team wrote. “Fire behavior is being driven by weather and critically low live and dead fuel moistures.”

Fire officials said the town of Meeker, power, oil and gas infrastructure that are “critical to the local rural economy and natural gas supply” and private structures along Colorado Highways 13 and 16 and County Roads 5 and 13 were among the areas of concern Monday. 

Evacuations and pre-evacuation orders remain in place in the area, with the Rio Blanco County Sheriff’s Office in a Facebook post Monday morning updating the evacuation status for certain zones to “ready” and “set.”

“The likelihood for fire to impact values is high,” fire officials said. “Resistance to control will also be high.”

Burning further east in Rio Blanco County, the Elk Fire had scorched 14,635 acres as of Monday morning, according to InciWeb. Containment on that blaze now stands at 30%, with firefighters making progress through the weekend. On Monday, officials said firefighters will continue to increase containment on the south end of the fire perimeter along County Road 8.

Garfield County public schools on Monday announced that the two wildfires burning not far from the county’s borders will delay the start to the school year due to interruptions to communication and poor air quality. School district officials cancelled school Monday and Tuesday with the goal of opening schools Wednesday.

On Saturday, the Colorado Department of Corrections safely evacuated the Rifle Correctional Center in response to the Lee Fire, with officials citing an “abundance of caution to ensure the safety of all individuals involved.”

With temperatures in the upper 70s to low 80s, Monday may be the coolest day of the upcoming week and could trend warmer each day until at least Wednesday, according to the incident management team. Gusty winds and dry conditions are also expected to continue this week.

As of Monday, there were 1,088 personnel responding to the Lee and Elk fires, according to the official Elk and Lee Fire Information Facebook page. That includes 12 aircraft, 24 hand crews and 60 engines.