John Phoenix had become very unhappy in Micanopy, and Rio bought him a ranch in Costa Rica, where he went to live. Rio, Rain, and Joaquin flew sometimes to see their father. By this time Arlyn had changed her name to Heart.
Rio was now responsible for the family's income. He bought a house for his grandparents in Palm Beach.
It was around this time when Keanu Reeves convinced Rio to take the role of Mike Waters in the film "My Own Private Idaho". River was very happy to do this film, since this could be the vehicle for his success as serious adult actor.
Five months before the beginning of the film, Rio and Keanu flew to Portland and
stayed with Van Sant. They used to go and stay with the hustlers to watch what they did. Rio's character was based on a hustler friend of Van Sant's, Mike Parker, who became a very close-friend of Rio's.
Rio became deeply immersed in this character. By November of 1990, Rio was a sad-eyed, pimply boy and dressed like a homeless person. You couldn't tell where Rio ended and Mike Waters began.
Some nights they used to play music in Van Sant's garage, and when everyone went to sleep, Rio used to go to his bedroom and went on playing until he couldn't anymore. After the six months on the set, Rio returned home. His friends didn't recognize him. He was temperamental and moody, and he was out of control, using drugs and alcohol daily.