Rockwell is joining Daniel Craig, Olivia Wilde and Harrison Ford in the film, based on the Platinum Studios graphic novel. The sci-fi Western explores what would happen if the traditional Old West enemies — cowboys and Native Americans — found the prairie attacked by aliens in mid-1800s Arizona.
Rockwell will play a bar owner named Doc who joins in the pursuit of the aliens.
Favreau will start shooting the film in June. Alex Kurtzman, Roberto Orci and Damon Lindelof wrote the script.
Source: Heat Vision