HBO has temporarily stopped production of its long-developing miniseries "Lewis and Clark" amid what's described as a "rough shoot," resulting in the departures of John Curran and director of photography Rob Hardy.

Deadline attributes the problems to "internal as well as external, weather-related factors." The cable channel confirmed the two exits.

Greenlit in February, the six-hour miniseries is an adaptation of Stephen E. Ambrose's 1997 book "Undaunted Courage" that stars Casey Affleck as Meriwether Lewis and Matthias Schoenaerts as William Clark, who are sent to search for a fabled all-water route to the Pacific. Charged by President Jefferson to explore the country west of the Mississippi, they encounter new terrain and the native tribes living there.

Tom Hanks, Gary Goetzman, Edward Norton, Brad Pitt, Dede Gardner, Tim Kelly and Adam Leipzig are executive producers.