Liam Neeson and Pierce Brosnan said they had the most fun in their career making this film. They loved westerns as kids, and were thrilled to finally to be in one.
Wes Studi's character is named Charon, which is also the name of the ferryman in Greek mythology who requires payment to transport the souls of the dead across the River Styx to the underworld. In the movie, Charon requires payment for the water both men drink and pass by.
Pierce Brosnan is on-screen for most of the first fifteen minutes of the movie, but he doesn't speak his first word until thirteen minutes and fifteen seconds in. Until then, he just grunts, groans, and screams of pain.
Colonel Carver's rifle in the film is an iron-framed Henry 1860, which indicates that it was one of the first four hundred built, before the more familiar brass was added in late 1862.
Xander Berkeley is an American who plays an Irishman. Liam Neeson and Pierce Brosnan are Irishmen who play Americans. Anjelica Huston lived in Ireland for a lot of her youth, and holds Irish citizenship.