Updated

The story behind the huge wildfire threatening Denver's suburbs got even more bizarre Wednesday, as prosecutors said they doubted a U.S. Forest Service worker's tale of accidental ignition and instead charged her with deliberately setting the blaze.

Terry Barton was being was being held without bail Thursday pending a bond hearing in U.S. District Court.

On Wednesday, a federal grand jury indicted her on charges of setting fire to timber in a national forest, damaging federal property, injuring a firefighter and using fire to commit a felony.

Barton, a 38-year-old mother of two and an 18-year Forest Service employee, faces up to 65 years in prison and a $1 million fine. Her attorney, Rick Williamson, declined to comment.

Authorities said Barton initially told them she was patrolling the Pike National Forest about 40 miles southwest of Denver when she smelled smoke and discovered the fire.

Over the weekend, having been confronted with inconsistencies in her original story, she said she had tried to burn a letter from her estranged husband within a campfire ring, but that the fire got out of hand.

Late Tuesday, sources said prosecutors doubted even that explanation, and Wednesday's indictment alleges that Barton "willfully and without authority set on fire timber, underbrush, grass and other inflammable material."

It also claims Barton "maliciously by means of fire damage" destroyed federal property and "such conduct directly and proximately caused personal injury" to firefighter Ryan Beyer, who suffered a broken arm.

Many of Barton's friends and relatives were stunned at the news. They described the veteran forestry technician as a dedicated and tireless worker, a well-liked person who loves the outdoors.

"I can't see her doing that," neighbor Richard Grenfell said from his Florissant home. "She loved the forest so much, why would she want to destroy it?"

Barton's mother, Wanda Haddock of Dunlap, Calif., said she spoke with her daughter by phone Wednesday and does not believe she intended to start the fire.

"She loved her job and she wouldn't do anything to threaten that job," Haddock said.

Barton's arrest over the weekend surprised colleagues and angered residents who have been evacuated. Since the fire began June 8, it has grown to 135,000 acres, destroyed 25 homes and forced the evacuation of 7,500 people.

Barton, who has two teenage daughters, and her family moved to Florissant near the Pike National Forest in the early 1990s from California. She started work for the Forest Service as a seasonal employee and less than a year ago was hired as a permanent, part-time employee.

Longtime family friend Connie Work said Barton is devastated by the charges against her and described Barton as a hard worker.

"She's very reliable," Work said. "She is a girl that goes out of her way to help others. She always has been that way and would do just about anything for anybody."

The Associated Press contributed to this report.