Yes, he started drinking again and I believe that he fell into either a ravine or into a body of water, perhaps the same body of water in which the brothers went fishing.
shareThanks for the spoiler warning. :(
shareAnyone who reads message boards on IMDB should not read them BEFORE they watch the movie if they have a problem with spoilers--ESPECIALLY after reading the OP's question or comment. It was clear the OP was asking about what happened to the father so you should not have continued reading the thread if you are so sensitive about spoilers.
shareHe died in a Marin County Jail in Jan 2006
share