Many of the buildings that made up the set of Deadwood (2004) had been altered or demolished by subsequent productions shot at the Melody Ranch, and the original blueprints lost. The Bullock home, for example, had been demolished to make way for Westworld (2016) and had to be rebuilt. Production designer Maria Caso, who won an Emmy for her work on the series, was forced to study the original series to accurately rebuild original landmarks.
The top hat worn by Joanie Stubbs (Kim Dickens) is the same gray top hat she wore in the original series, but it was refashioned with brown fabric to make it look new (a common practice in the 19th century). The costume designer could not find a new hat that fit her as well, and Dickens has kept the original hat all these years.
After Season 3 ended, David Milch made a handshake deal to make two Deadwood movies to conclude the series with then-HBO chairman and chief executive Chris Albrecht. Mr. Albrecht was arrested in Las Vegas for assaulting his girlfriend in a parking lot. After HBO fired Albrecht, the Deadwood movies were not made as planned. It has been speculated that if a contract had been signed to make the two Deadwood movies before Mr. Albrecht was fired, the conclusion of the series would've most likely been completed over a decade ago.
Molly Parker (Alma Garret), who was also shooting her series Perdus dans l'espace (2018) in Canada, traveled back and forth to Los Angeles to shoot her scenes in the film. She would be so exhausted between takes that she would lie on the floor, in full costume with corset, to get some rest.
Nic Pizzolatto helped David Milch write the Deadwood film, which eventually led to Milch writing on the third season of Pizzolatto's True Detective (2014).
Garret Dillahunt: , who played two characters in the series, Jack McCall and Francis Wolcott, here as "Drunk No. 2", who yells out about his father dying in the street.