A series of wildfires that sparked across Colorado this week burned nearly 15,000 acres, but fire crews are starting to take control.

As of Saturday, only one fire — the Bucktail fire, burning on nearly 3,000 acres in Montrose County near Nucla and the Uncompahgre National Forest — was 0% contained, according to fire officials.

The fire hasn’t damaged any homes, and no evacuations have been ordered, according to the Inciweb website, which monitors wildfires.

The three fires actively burning across Colorado’s Front Range all saw large jumps in containment Saturday.

As of Saturday evening, Jefferson County’s Quarry fire was 20% contained, Larimer County’s Alexander Mountain fire was 32% contained and the Stone Canyon fire burning in Boulder and Larimer counties was 53% contained.

“We’re getting to the point where we’re not running from the fire, but we’re taking control of the fire,” Jefferson County sheriff’s spokesperson Mark Techmeyer said Saturday evening.

The Quarry fire and the fatal Stone Canyon fire are believed to have been human-caused, and county officials have opened arson investigations.

Jefferson County sheriff’s investigator Kevin Bost said Friday that the Quarry fire near Dear Creek Canyon likely was caused by people, but he didn’t specify whether investigators believed it was intentional or accidental. He also did not say what evidence investigators found.

No updates on the Jefferson County investigation were available Saturday, but Techmeyer said an arson dog from the state had arrived to sniff out clues. Fire officials asked anyone with tips or home security camera footage that may be helpful to call 303-271-5612.

To the south, Stone Canyon fire investigators are receiving help from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives to determine the cause of the fire, which has burned 1,553 acres near Lyons.

The Stone Canyon fire has killed one person, injured two firefighters and charred at least five homes, fire officials said.

Meanwhile, the cause of the Alexander Mountain and Bucktail fires remain under investigation.

Larimer County sheriff’s spokesperson Joe Shellhammer said the forensics investigation team hiked up Saturday to the fire’s origin site on Alexander Mountain, but they haven’t been able to determine the cause –whether human or natural — yet.

The Quarry fire grew 20 to 30 acres overnight Friday, bringing the total burn area to about 500 acres, fire officials said Saturday morning. The fire is the smallest of the four but is the closest to densely populated areas and has the toughest terrain.

Techmeyer said firefighters are not only battling heat in the area but also rattlesnakes, bears and mountain lions.

Larimer County’s Alexander Mountain fire is the largest in Colorado.

At 9,668 acres, the Alexander Mountain fire is three times the size of the second-place Bucktail fire in Montrose County.

The Alexander Mountain fire has destroyed nearly 50 homes and buildings and damaged four others, Larimer County officials said Saturday. The burnt homes were found along Cedar Creek Road, Spruce Mountain Drive, Green Ridge Road, Possum Court, Palisade Mountain Drive, Snow Top Drive and Bobcat Drive.

However, the Alexander Mountain fire also had the largest jump in containment Saturday — fire crews were able to solidify containment lines around 32% of the fire. As of Friday evening, the flames were only 5% contained.

“Containment doesn’t happen throughout the day,” a Larimer County spokesman said in a Saturday evening news conference. “Containment happens in large acres. … We may not show containment movement each day, but that doesn’t mean progress isn’t happening.”

He said crews have to build the fire line, mop up the area, secure the line and hold it for several days before fire officials can have the confidence to say the area is fully contained.

Although Alexander Mountain fire officials haven’t lifted evacuation orders, Shellhammer said they’re discussing reducing the evacuation footprint during Saturday night and Sunday morning meetings.

If evacuations are lifted, Shellhammer said it would be announced Sunday afternoon.

As of 5 p.m. Saturday, mandatory evacuation orders had been lifted for two neighborhoods in Jefferson County, according to Techmeyer.

Residents in the Deer Creek Mesa and Kuehster neighborhoods were able to reenter their homes Saturday night but had to have a badge issued from the evacuation center set up at Dakota Ridge High School, Techmeyer said.

The evacuation center issued preliminary badges for all neighborhoods between 10 a.m. and 3 p.m. and will reopen during the same hours Sunday, Techmeyer said.

Techmeyer said it’s not enough to show up with a driver’s license and show an area address — residents must have a colored badge to enter because roads in the area will remain closed to the public for several days.

Deer Creek Mesa is the closest neighborhood to the fire — about a quarter-mile from the flames — but Techmeyer said it’s also near the most secure containment line.

Techmeyer said Kuehster was chosen for evacuation orders to be lifted for the opposite reason — it’s the farthest from the flames, and crews are confident the fire won’t grow enough to reach the neighborhood.

The McKinney Ranch, Murphy Gulch, Sampson and Maxwell areas remain under mandatory evacuation orders, according to the county’s evacuation map.

The Hilldale Pines, Oehlmann Park, Silver Ranch, West Ranch, Homestead and Silver Ranch South neighborhoods are on pre-evacuation notice. Now, Deer Creek Mesa and Kuehster have joined them.

If evacuation orders for the Alexander Mountain fire are lifted Sunday, fire officials said they plan to institute a similar system for entry to the Quarry fire — at least for areas near Cedar Park and Storm Mountain.

All of the fires across the state led Colorado Department of Public Health and Environment officials to issue air pollution alerts across the Front Range and in Montrose County on Saturday.

Smoke, soot and ash from wildfires can enter people’s lungs during outdoor activities and cause breathing difficulties, especially in the elderly, young children and those with heart and lung diseases such as asthma.