Rescue workers from neighboring states have joined in a search for a 12-year-old girl reported missing after leaving her family's home in southwestern Pennsylvania to ride her all-terrain vehicle.

Gabrielle Miranda Bechen has been missing since early Tuesday morning, when she went riding on roads and trails near the Greene County home, state police said.

Bechen's parents alerted police when she did not return by 2 p.m., prompting troopers and local firefighters to search through the night.

By Wednesday, search teams from West Virginia, Maryland, Virginia, Delaware and the Washington, D.C., area had joined local authorities and volunteers in scouring a wooded area covering about three miles bordering West Virginia.

They searched on foot and riding ATVs, some using scent-tracking dogs, as a state police helicopter flew overhead.

The family is offering a $500 reward for information leading to the return of the girl, who is described as 4-foot-9 and 77 pounds, with brown eyes and brown hair with blonde highlights. She was riding a small black ATV with flame decals on its fenders.