ST. CLOUD, Minn. — The search continues in Utah's Canyonlands National Park for a biology professor from Minnesota.

Park spokesman Paul Henderson says Jerry O. Wolff had a permit to stay in the park until last Friday.

As of Wednesday, searchers still haven't found any evidence of the 65-year-old professor from St. Cloud State University. He's in an especially rugged part of the park.

Henderson says airplanes and search dogs will still go out at least once a week, and rangers remain in the area. Wolff had a backcountry permit and was alone. He hired someone to drop him off.

Chief Park Ranger Denny Ziemann says Wolff is in an area that's accessible only by all-terrrain vehicles.