Robert Redford hired him as an advisor when "The Horse Whisperer" was going into production and, as the movie's director and star recalls in Ms. Meehl's documentary, ended up modeling much of his character on Buck's gentleness and humanity.
WSJ: Buck | Green Lantern | City of Life and Death | Mr. Popper's Penguins | Champion Tale of a Horse Guru | Film Reviews by Joe Morgenstern