Colonia Morelos, the town Billy enters, was actually founded in 1900, but the majority of the Mormon colonies in Mexico do date back to the 19th century, beginning in 1885.
The towns making up the colonies were situated near the Sierre Madre mountains, in the states of Chihuahua and Sonora. The original colonists had migrated to Mexico in order to escape persecution in the United States for the Mormon practice of polygamy.
In 1912 the colonies were evacuated due to anti-American sentiment during the Mexican Revolution. Today, only Colonia Juárez and Colonia Dublán in the Casas Grandes river valley remain active Mormon settlements.