The 32-year-old had been missing since 6 October. Her body was found in a ravine near Seattle following a search of the area by friends and family.
Her father, Charles Upham, confirmed her identity to authorities.
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Police have confirmed they have found the body of missing actress Misty Upham
Police Commander Steve Stocker said there was no evidence or information "to believe there is foul play".
Native American Misty, who earned critical acclaim for her roles in films including August: Osage County, Frozen River and Django Unchained, was last seen on 5 October.
Her father first reported her missing, and said she had stopped taking medication for bipolar disorder and anxiety.
Misty had moved to the Seattle area to help care for her dad, who had suffered a stroke. She was reportedly staying on the Muckleshoot reservation, and was last seen walking from an apartment south of Seattle.
Misty Upham won critical acclaim for her role in the 2008 film Frozen River
Despite her feted performances on camera, the star once described herself as "painfully shy".
"When I'm in front of the camera, or talking to people as an actress, and not as myself, it's like I become another person," she said. "Somehow possessed with somebody who is worth talking to. Because at home people could care less about what I have to say."
Her August: Osage County co-star Meryl Streep was among the first to pay tribute to the late actress.
"So, so sad to hear this news - all our thoughts are with her family and with her beautiful spirit," she told the Hollywood Reporter on learning of Misty's death.