Celina Cass was last seen on Monday at her home in Stewartstown, which is about a mile away from the Canadian border.
Dive teams were set to be brought in Sunday, but there was no word on where they're expected to search.
Investigators have already combed much of the girl's neighborhood.
Saturday, the girl's family was allowed to return to their home. They'd been staying at a motel while investigators searched the property for clues.
There was no word yet on whether anything was found, but police did tow away a red pickup truck.
Fliers featuring photos of the girl with a gap-toothed smile were put up throughout Stewartstown and neighboring communities. Residents have passed out purple and pink ribbons and held vigils.
Celina is 5 feet 5 inches tall, weighs about 95 pounds and has hazel eyes and waist-length brown hair.
The Associated Press contributed to this report.