Jessica Chastain is heading west in the first trailer for “Woman Walks Ahead”.

Based on real events, the film stars Chastain as the widowed Catherine Weldon, a woman who journeys from New York to North Dakota in 1890 to paint the famous Chief Sitting Bull (Michael Greyeyes) as tensions mount between the Lakota and the U.S. army. After bonding during Sitting Bull’s portrait sessions, Weldon is deemed a threat by the army, including Sam Rockwell’s Col. Silas Groves, who are still sore over Sitting Bull’s victory over Lt. Col. Custer almost 15 years earlier. As the risk of the army’s retaliation against the Lakota reservation rises, Sitting Bull and Weldon find themselves drawn even closer together in big sky country.

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“Woman Walks Ahead” is directed by Susanna White from a script by Steven Knight (“Eastern Promises”).

The actress shared several photos from the set during filming in 2016.

After debuting at the Toronto International Film Festival last September, the film is slated to air on DirectTV on May 31 and in select theatres on June 29.