A 13-year-old girl's escape from a rural home where she was held captive for three months by a Wisconsin man charged with murdering her parents helped break the case and she should be treated as a hero, the local sheriff has said.

Jayme Closs is with her aunt after her rescue on Thursday and has been reunited with the rest of her family and her dog, Barron County Sheriff Chris Fitzgerald told reporters.

Thousands of volunteers and hundreds of law enforcement officers had searched the small town of Barron after Jayme's parents were found shot dead in their home in October, their front door blown open with a shotgun and their daughter gone.

Jayme was targeted by suspected kidnapper Jake Patterson, 21, who carefully planned her parents' murder, even shaving his head to avoid leaving forensic evidence at the crime scene, Sheriff Fitzgerald said.

"Jayme was the target," he said.

"The suspect had specific intentions to kidnap Jayme and went to great lengths to prepare to take her."

Relying on what Sheriff Fitzgerald  called "the will of a kid to survive," a disheveled Jayme escaped the house in the tiny town of Gordon where she had been held captive, about 100km north of her home in Barron.

Her captor was not at home when she managed to flee, Sheriff Fitzgerald said. She was found by a woman walking her dog on Thursday afternoon.

"Jayme is the hero in this case. She's the one who helped us break this case," Sheriff Fitzgerald said.

Jayme spoke to investigators yesterday after spending a night in the hospital for evaluation. Authorities did not offer any details about the conditions of her captivity or how she had managed to escape.

Less than 15 minutes after Jayme's rescue, Mr Patterson was taken into custody after police pulled him over, based on Jayme's description of his vehicle.

"The suspect was out looking for her when law enforcement made contact with him," Sheriff Fitzgerald told a news conference,adding police were not seeking any other suspects in the case at this time.

Police are now trying to work out why Patterson targeted Jayme.