Photos provided by the FBI show Damron with shorter hair last year. Courtesy, Maine State Police

AUGUSTA — The FBI is offering a reward of up to $15,000 for information leading to the safe return of Stefanie Damron or the arrest and prosecution of anyone involved in her disappearance.

The reward was announced at a joint news conference with the Maine State Police and the Federal Bureau of Investigation at the Department of Public Safety on Monday.

“Any detail, no matter how small, could be helpful,” Jodi Cohen, special agent in charge of the FBI Boston Division said in a written statement.  “Stefanie’s family desperately wants to know where she is, and we are fully committed to helping our law enforcement partners exhaust every investigative resource to find her and bring her home.”

The 14-year-old from New Sweden has been missing since late September, when she was last seen walking out of her house and into the woods on West Road, wearing blue jeans, a blue long-sleeved shirt and black Harley Davidson hiking boots.

Damron was 13 when her parents reported her disappearance on Sept. 24, and has since turned 14. She is described as 5 feet tall with green eyes and shoulder-length brown hair. There have been no credible sightings of her since, said Kimberly Milka, FBI Boston assistant special agent in charge.

Damron is home-schooled and has limited access to social media, according to the FBI. She had no electronic devices with her when she left, Maine State Police Major Scott Gosselin said during the news conference.

Running away to the woods behind her house is “not uncommon behavior” for her, Gosselin said. But being gone for so long was unusual, which prompted her parents to report her disappearance the next day.

Like any case involving a missing minor, the Maine Department of Health and Human Services was notified, Gosselin said. He would not share further information about the department’s investigation.

Some tips from the public suggest Damron had been in contact with someone through social media, said Maine State Police Lt. Darrin Crane. But “at this point, everything is still on the table,” he said.

Despite “extensive” investigation from multiple crime units and the FBI’s Child Abduction Rapid Deployment Team, police have been unable to locate Damron for months.

“In any missing persons case, especially so close to the border like this, you’re going to want to involve the FBI,” Gosselin said. New Sweden is in northern Aroostook County near the border with Canada. “Nothing has been ruled out or eliminated. Crossing state lines is certainly one of those possibilities.”

A few days after Damron was reported missing, the Maine Warden Service conducted an “expansive grid search” with Maine State Police, deploying canines and canvassing the woods near West Road.

With temperatures getting colder, Gosselin encourages hunters in the area to be extra vigilant for signs of Damron.

Maine State Police ask anyone with information about Damron’s location to call the regional communication center Houlton Barracks at 800-924-2261 or 207-532-5400. You may also contact the FBI at 1-800-CALL-FBI, your local FBI office, or submit a tip online at tips.fbi.gov.