After police in Auburn, Washington, found a body at the bottom of a 150-foot embankment near Forest Ridge Drive near the White River on Thursday, the actress's father, Charles Upham, confirmed her identity to the authorities, according to the Hollywood Reporter".
Cause of death has yet to be determined.
"We waited at the site where the team found the body," Seattle-based filmmaker Tracy Rector, a longtime friend of Upham's and a member of the search party, said late Thursday night. "It took about 5½ hours to confirm. Then we gathered around her body to say prayers and now we're all gathered at the church."
The 32-year-old Native American actress, known for her roles in August: Osage County and Django Unchained, had been missing since Oct. 6.
Upham was born on the Blackfeet reservation in Montana, and her family moved to Seattle when she was 8, reported the Seattle Times, which quoted an interview she gave Distinctly Montana Magazine earlier this year: "I needed to leave [the reservation]. My idea was to go to the nearest city and go to the first theater I could find. I would watch movies, take breaks and eat."
During last week's search for her, her father spoke out about her battle with mental illness, saying a change in medication had left her struggling with depression and panic attacks.
Police have responded to suicide calls at her apartment four times over the past year, Stocker told PEOPLE on Saturday.
Still, in an Oct. 12 Facebook post, Upham's father said he didn't think his daughter committed suicide.
"I feel that she has been hurt by accident or someone has put her in harm's way," he wrote.
Friend of missing actress Misty Upham tells me a search party of three found her purse and then a body. Awaiting official identification.— Graham Johnson (@GrahamKIRO7) October 16, 2014
Friend of Misty Upham says relatives and members of the Native community organized today's search. Awaiting ID on body found.— Graham Johnson (@GrahamKIRO7) October 16, 2014
Additional reporting by MICHELE CORRISTON