Gerald Wayne Schetzle, who went by the name Wayne Shannon in his TV career, was found on April 28 south of Grangeville.
Officials believe Schetzle's body had been there for several months.
The medical examiner found no signs of physical trauma and toxicology results are pending.
Investigators say that due to evidence found at the scene, they believe he took his own life.
Shannon was a reporter in the San Francisco area in the 1980s when he worked for KRON-TV and also worked at CNBC.
Police say he was most recently living in Lewiston. He was 64 years old.