Heath Ledger and Jake Gyllenhaal are in negotiations to play gay cowboys in the next film to be shot by The Hulk director Ang Lee, sources said. Brokeback Mountain revolves around two men who meet one summer in Wyoming and form a bond and love that spans 20 years. The film tracks that time period and their evolving relationship. The start date has yet to be determined. Adapted by Larry McMurtry and Diana Ossana from a short story by The Shipping News scribe E. Annie Proulx, the Focus Features project has long been regarded as one of the great screenplays that never got produced, industry sources said. Ledger most recently starred onscreen in The Order. Late last year he finished up work on Brothers Grimm opposite Matt Damon, Jonathan Pryce, and Peter Stormare. Gyllenhaal's most recent big-screen appearance was opposite Jennifer Aniston in The Good Girl. His upcoming films include The Day After Tomorrow and Proof.