The body of Benjamin Barnes, 24, was found chest deep in snow. About 200 law enforcement officers had been searching the park.
Barnes body was found a day after police said he shot and killed park Ranger Margaret Anderson, 34, during a traffic stop. Anderson was a mother of two.
Authorities said the shooting happened just before 11 a.m. near the Longmire Ranger Station in the southwestern part of the 368-square-mile park in Washington state. Barnes fled on foot after the shooting.
Barnes was also a suspect in a shooting that left four wounded in Skyway, Wash., earlier Sunday.
According to ABC News, Barnes' car was found abandoned, equipped with weapons and body armor. He had military experience and possessed skills to survive in the wild.
Barnes' family said he served one tour of duty in Iraq. His estranged wife said he suffered from post-traumatic stress disorder.
Barnes attended Jurupa Valley High School in Mira Loma, but his classmates said he was rarely there.
"I see him skip school," said classmate Weman Reyes. "At school, I never saw him at all. He was just like a loner."
Reyes, who grew up with Barnes in Riverside, said he can't believe the 24-year-old went from Boy Scout to accused killer.
"I was surprised. I mean I haven't heard from him in a long time. To hear this, it's surprising," said Reyes.
The Associated Press contributed to this report.