Alain Goldman and Molly Hallam of Legende Films are producing the project.
French director Laure de Clermont-Tonnerre is helming from his own script, co-written with Mona Fastvold and Brock Norman Brock, reported Variety.
In the film, Schoenaerts is playing a violent convict, who is given the chance to participate in a rehabilitation therapy program involving the training of wild mustangs and Stewart is his eager, strung out cellmate.
Sarandon will play the prison therapist and Adlon will portray Schoenaerts' character's daughter.