What historical period does "The Sisters Brothers" take place?

The Sisters Brothers takes place during the California Gold Rush, mainly in the American West in 1851.

Patrick deWitt’s story follows Eli and Charlie Sisters, two hired guns sent from Oregon City to California to kill the prospector Hermann Kermit Warm. Their journey passes through the rough frontier world associated with the Gold Rush, including prospecting camps, dangerous trails, San Francisco, and isolated settlements.

The historical setting is important because gold fever shaped the region’s population, economy, and violence. Thousands of people travelled west hoping to find fortune, while towns and informal communities appeared rapidly around mining activity. The novel uses that unstable environment for its darkly comic western story, blending real frontier conditions with fictional characters and events.

The title refers to the two brothers, not to a historical family or mining claim. The novel was published in 2011, while the film adaptation, starring John C. Reilly and Joaquin Phoenix, was released in 2018. Both versions use the same 1851 Gold Rush-era setting, although some plot details differ.