Misty Upham's father says she fell to her death trying to flee police

The family of Misty Upham believes she fell accidentally to her death.

Police said Thursday that they believe a body found in the Seattle suburb of Auburn is that of Misty Upham, a missing actress who has appeared in August: Osage County, Frozen River and Django Unchained, KIRO-TV 

"Misty was a beautiful soul and a phenomenal actress who had seemingly never-ending reserves of talent," Daniel Barnz, her director in the upcoming comedy-drama Cake, tells PEOPLE. "She was an open and giving person. I'm heartbroken over her death."

Police in Seattle say they believe the body of the missing actor Misty Upham has been found. A woman's body was found in a ravine near the White river at about 1pm on Thursday, the police spokesman, Steve Stocker, said. Items with Upham's name on them 

Update, Thursday at 9:17 p.m. PT: The body of actress Misty Upham has been transferred to the King County Medical Examiner's office in Washington state for positive identification, after a nearly five-hour recovery operation. Upham's manager confirmed