I picked up a reference to this in "Breaking Bad" that nobody seems to have noticed. SPOILER ALERT
The Breaking Bad character Mike Ehrmantraut's death by the river in the Breaking Bad episode, "Say My Name" is very reminiscent of the death of Slim Pickens' character in Pat Garret & Billy the Kid.
Also, earlier in that episode, Mike had literally "put his guns in the ground". A reference to the lyrics of Bob Dylan's song, "Knocking on Heaven's Door", which provided the soundtrack to Pickens' death scene.
I just posted this on the IMDB trivia page for PG&BTK. Hopefully they will include it.