The 32-year-old Native American actress was reported missing by her father on October 6, after she was last seen walking by herself from an apartment the day before near Auburn, some 32km south of Seattle, Auburn Police Commander Steve Stocker said.
Auburn police were alerted that a body had been found in a wooded area at the bottom of a 46m embankment near the White River in Auburn, south of Seattle, Stocker said in a statement.
A purse with Upham's identification was at the scene, but a medical examiner had not made a positive identification or a determination of cause of death, Stocker said.
A family member was in the area searching for her and discovered the body and called the police, Stocker said.
Police responded to numerous suicide calls in the past year at the same apartment, Stocker said, and Upham's parents told police their daughter was on medication for mental health issues.
Upham was nominated for an Independent Spirit Award for her supporting role in the 2008 crime drama, "Frozen River." She also appeared in the movie ''Django Unchained''.
