Walter Salles on Kristen + Interview of Kristen:
Still, Salles was always thinking of the film. He began casting in 2005.
Kristen Stewart, long before she became an A-list star with the Twilight Saga, was sought to play Marylou, the woman who accompanies Dean and Sal on their travels. Salles credits two notable friends - composer Gustavo Santaolalla, who worked on The Motorcycle Diaries, and Alejandro Gonzalez Inarritu, the Mexican director of 21 Grams, Babel and Amores Perros - for the casting inspiration. Both were invited by Sean Penn to see the first cut of his 2007 film, Into The Wild, which featured Stewart in an eye-catching supporting role. "They called me and said, 'Listen, for Marylou - stop looking! There is this great young actress and that we've never seen before. She's really unique and very talented. She's right for the role.' I remember writing down the name so I wouldn't forget! I'd never heard the name Kristen Stewart!"