Police received a report late Friday night that the woman had gone missing during a walk earlier that evening. She was found just before 7 a.m. Saturday morning near a levee behind a baseball field.
The woman was taken to St. Anthony Hospital and later flown to Oregon Health & Science University in Portland.
Officials identified the person of interest Monday as Danny Wu. Initially, they did not release his name.
Anyone with information about this case are encouraged to call the Pendleton Police Department at (541) 276-4411 or the Umatilla County Dispatch Center at (541) 966-3651.