I didn't like it
Please don't jump on what I this post and say I shouldn't say anything against the movie, if I don't like it I should shut up and go away, etc. I made it clear in the heading that I don't like it, and if someone doesn't want to read a negative reaction, they shouldn't read it. But personally, I find negative responses valuable, as long as they don't degenerate into the kind of name-calling insults IMDB posters sometimes indulge in. If I am trying to decide whether to watch a movie or not, I like to go to Rotten Tomatoes and to IMDB and read the pros AND cons, maybe watch a trailer, and then decide whether it sounds like something I want to invest my time in watching.
Blackthorn seemed to me to be endlessly boring. I'm glad I didn't pay money to see it in a theater, or buy the DVD, but watched it on TV where I could record it and fast forward through the many interminable scenes of Nothing Happening.
It's not that I want ACTION, I don't even usually like "action movies." But there should be SOMEthing of interest going on, like interesting characters, interesting dialogue, interesting plot, interesting historic or geographic information, Something.
This movie seemed to me mainly an attempt to play off the fame of the wildly successful "Butch Cassidy and the Sundance Kid," which by the way, had ALL of the "interesting" aspects listed above, plus a lot of humor.
I won't even bother to list the numerous "unlikely" things portrayed, other people are doing that here, but they add up to a sense of general falsity.
Something I did like, however, was the background music. In places the solo acoustic guitar sounded something like the soundtrack solo guitar in Brokeback Mountain, and it added some much needed feeling. I also liked the Bolivian scenery. And the co-star, whose face actually showed various expressions, unlike Sam Shepherd's frozen antique visage.