HBO has greenlit the miniseries “Lewis and Clark” from exec producers Edward Norton, Brad Pitt, Tom Hanks, Dede Gardner and Gary Goetzman. Casey Affleck and Matthias Schoenaerts will star as Meriwether Lewis and William Clark, respectively.

Michael Lombardo, president of HBO programming, made the announcement Friday.

Based on the book “Undaunted Courage,” by Stephen E. Ambrose, the six-hour historical drama follows the journey of the Corps of Discovery and its captains, Lewis and Clark, on their mission to deliver President Thomas Jefferson’s message of sovereignty, as they search for his fabled all-water route to the Pacific. “Lewis and Clark” tells the story of America’s first contact with the land and native tribes of the country west of the Mississippi River.

“In ‘Lewis and Clark,’ we can see American idealism and the breathtaking natural beauty of the continent, as well as the complexities and tragedies of what came to be known as America’s ‘manifest destiny,’” said Lombardo. “We are tremendously excited to bring together this incredible group of talents to tell a seminal American story.”

The miniseries hails from HBO and National Geographic Studios and is produced by Playtone, Plan B and Class 5. John Curran (“The Painted Veil”) will direct, and Michelle Ashford (“The Pacific”), Curran and Norton will serve as writers.

Production begins this summer.