Portland police Sgt. Pete Simpson says Anna Schmidt was last seen Sunday.
Schmidt was reported missing Wednesday, and her car was found a day later near Bonneville Dam. There were no signs of foul play at the car.
Simpson says Schmidt is a hiker and she recently bought a new tent and backpack. Searchers were looking for her Friday.
Schmidt is 5-foot-4, 125 pounds and has brown hair and brown eyes. Anyone who may have seen her in the gorge or elsewhere is asked to call 911.