By Rusty Surette, NEWS 9

YELLOWSTONE NATIONAL PARK, Wyoming -- A search is underway in Yellowstone National Park for an Oklahoma City man.

Peter Louis Kastner, 25, has been missing since Monday according to federal authorities.

During a routine patrol early Monday morning, rangers found a 2010 Red Cadillac STS sedan with Oklahoma license plates parked at the Hellroaring Trailhead, 3.5 miles west of Tower Junction.

The vehicle, which had obviously been parked overnight, was not associated with an overnight back country permit, according to a Yellowstone National Park news release. A check showed Kastner had rented the vehicle several days earlier. Few personal belongings were discovered in the car.

A preliminary search and questioning of hikers, backpackers, and area businesses have failed to turn up any information on Kastner's whereabouts. Dog teams are being added to the search effort this afternoon.

Kastner is described as 6'1" and 185 pounds, with brown hair and hazel eyes.

Rangers believe Kastner may have been in the area for up to two weeks, and may not have been using his own name in any contact with individuals or businesses.

Anyone with information regarding Kastner is asked to call Yellowstone National Park at 307-344-7381.