Updated

A former Forest Service worker who admitted starting Colorado's largest wildfire surrendered Monday to begin serving a six-year federal prison sentence in Texas.

Terry Lynn Barton, 39, turned herself in at the Carswell Federal Medical Center in Fort Worth, Texas. Medical centers take prisoners with serious physical or mental heath problems, according to the Federal Bureau of Prisons.

There was no indication that Barton was ill when she was sentenced, but she was ordered to undergo mental health counseling after she was arrested.

In her first interview since the fire, Barton said she wasn't thinking about the fire danger when she burned a letter from her estranged husband, whom she was trying to divorce. The fire grew to 138,000 acres and destroyed 133 homes.

"It was just the state of mind I was in and I didn't do it on purpose," she said in an interview broadcast on Denver's KCNC-TV Monday night. "It just upset me and I thought: 'I'm not going to let him get to me. I'm going to get this divorce.'"

Barton, whose job included watching for fires banned because of dry conditions brought on by drought, said she drove away but looked back to see she had started a fire. She helped battle the inferno for days, too afraid to come forward and admit her guilt.

"There wouldn't be a day that would go by that I could live with myself knowing that I destroyed something that I loved so much -- and that's the forest -- and to hurt people, because I love people," she said.

Barton also said she accepts her prison sentence and understands the consequences of her actions.

In Denver, federal prosecutors said Monday they had filed a motion seeking to preserve the right to appeal a judge's decision to deny restitution in the case.

The federal government had requested $14.7 million to cover firefighting costs and restoration of the Pike National Forest. The request was denied by a federal judge when he sentenced Barton on Feb. 21 on two arson charges.

Barton also has been sentenced to serve 12 years on a state arson charge. Her lawyer has appealed, claiming the judge might have had a conflict of interest because he was personally affected by the fire.

Prosecutors contend Judge Edward Colt treated Barton fairly and should not be removed from the case.

Before sentencing Barton this month, Colt said he fled his home for one night after seeing heavy smoke from the fire.

Colt has not decided how much Barton must pay in restitution for the fire, which destroyed 133 homes.

Prosecutors said it caused at least $29.9 million in damage.