Updated

Just last week, veteran U.S. Forest Service worker Terry Barton was explaining how she stumbled upon what would become the largest wildfire in Colorado history.

"I tried to throw dirt on it, but the winds were going crazy and it was just too late," she told The Gazette of Colorado Springs. "I think I know in my heart that there was nothing I could do."

That story didn't add up to investigators who arrested the 38-year-old Barton on Sunday and accused her of igniting the blaze. According to authorities, Barton said she started the fire as she tried to burn a letter from her estranged husband at a campfire site.

The sprawling fire is about halfway contained. Hundreds of firefighters remain on duty and 5,400 residents are still waiting to go home.

Many have been angered by the arrest of an 18-year Forest Service employee for a fire that has destroyed 25 homes, burned 103,000 acres and cost nearly $10 million to fight. Barton's colleagues are bewildered.

"It's tough. We still have a job to do," Forest Service spokesman David Steinke said. "A lot of people have called, telling us they are behind us and letting us know they're not blaming us.

"They trust us with their public lands. It feels good that people support us and realize that one person did this unthinkable act," he said.

Federal authorities say Barton confessed over the weekend and have charged her with setting fire to timber in a national forest, damaging federal property and making false statements to investigators. If convicted, she faces up to 20 years in prison and a $250,000 fine.

Barton was ordered held without bail at the request of U.S. Attorney John Suthers.

"She would return to a community in which there is considerable hostility toward her," Suthers said.

Barton appeared in court Monday in handcuffs. Her voice quavered as she told a magistrate that she understood she could be sentenced to prison. Her public defender, Rick Williamson, refused to comment.

Suthers refused to say why Barton was accused of deliberately setting the wildfire but had not been charged with arson. He said more charges could be filed.

The fire began June 8 and quickly roared out of control, burning across the foothills between Colorado Springs and the suburbs southwest of Denver. Investigators at first said it had been started by a campfire, then backed off and said it was somehow human-caused.

It was a week's worth of forensic work that led to the arrest.

Barton initially told investigators she was patrolling the Pike National Forest when she smelled smoke and went to investigate, according to affidavits. She said she found a 20- by 20-foot fire near a campsite, called for help and vainly attempted to put it out.

But investigators found evidence that the fire was set deliberately to look like an escaped campfire. They looked at the time it started and concluded that the fire spread too quickly to have come from a campfire.

"Given prevailing conditions and the distance Barton reportedly was from the point of origin at the time she smelled smoke, the fire could not have been the size reported by Barton when she allegedly discovered it," Agriculture Department agent Joseph Crook wrote.

Confronted with the evidence, authorities said Barton confessed Saturday.

Crook said Barton told them she was on patrol when she looked at a letter she had received that day from her estranged husband, grew angry and decided to burn it. She walked to the campfire ring and ignited the letter with matches, Crook said.

After she drove away, she turned back and saw the fire was on the ground, Crook said. She said she tried unsuccessfully to put it out.

Barton's husband, John, said he was not living at home with Terry and their two teen-age daughters, but had visited last week to be with the girls while Terry worked on the fire.

John Barton told The Denver Post his wife has been upset, but has not told him much.

"She's been staying late. Some nights, she hasn't come home," he said.

Former prosecutor Craig Silverman said it would have been difficult for authorities to make an arrest had Barton not confessed.

"I don't care how good the forensic evidence was, if she hadn't said it, no one would have believed someone from the Forest Service was responsible," Silverman said.

He also said it will be difficult to make the government pay for the damage because Barton did not set the fire while doing her regular duties. He said the government still may offer to compensate victims.

"This is a public relations disaster for the Forest Service," Silverman said.