Sienna Miller and Sam Worthington have teamed up with Kevin Costner for his new project, Horizon.
The Oscar winner, 67, co-wrote the script for the epic historical drama, which will begin production in Utah on August 29.
In addition to starring in the film, he will also direct, produce and finance the wide-ranging story, which takes place over a 15-year period of expansion pre and post Civil War, according to Deadline.
Passion project: Kevin Costner, 67, is set to begin work on his passion project, Horizon, later this month. The film is expected to be the first in a trilogy about US expansion before and after the Civil War
The upcoming Western will mark the Yellowstone star's first time stepping behind the camera since 2003's Open Range.
Jamie Campbell Bower, 33, who plays the evil Vecna in Stranger Things, is also listed as a member of the cast on IMDB.
Sienna, 40, expressed her delight with the casting, saying, 'I am so excited to go on this epic journey with such a legendary actor and director at the helm. The story is riveting. I am very honored to be a part of it.'
Excited: Sienna Miller, 40, and Sam Worthing, 46, have both expressed their excitement to take part in the project which begins production August 29 in Utah
New frontier: Jamie Campbell Bower, 33, who plays the evil Vecna in Stranger Things, is also listed as a member of the cast
Sam, 46, agreed, 'I am very excited and humbled to go on this incredible and important journey with Kevin, who is one of the industry’s finest and inspiring storytellers.'
Horizon is expected to be the first film in a trilogy and is expected to have the same kind of sweep as the Academy Award-winning Dances With Wolves, which won 12 Oscars, including Best Director.
The No Way Out actor has been so immersed in preparations for the film that he had to skip the game between Chicago Cubs and Cincinnati Reds Thursday played at the Field of Dreams baseball diamond in an Iowa cornfield, immortalized in the touching 1989 film.
Yellowstone: Kevin has starred in and helped produce Yellowstone for four seasons
Directing: The Oscar winner's last time behind the camera was for 2003's Open Range which won the 2004 Western Heritage Award
He did contribute to a remembrance to actor Ray Liotta, who played Shoeless Joe in the movie. The Emmy winner died in May while shooting a film in the Dominican Republic.
Sienna Miller just completed working with Scarlett Johannsson and Kristen Scott Thomas in My Mother's Wedding. The film marks the directorial debut for the Three Weddings and a Funeral star.
Sam Worthington will be seen next on the big screen in Avatar: The Way Of Water. The long awaited sequel is set to open in theaters December 16.
Dances With Wolves: Kevin struck Oscar gold with his directorial debut, 1990s Dances With Wolves. The film won seven Academy Awards including Best Director and Best Picture