Old Las Vegas Mormon Fort State Historic Park centers on the Old Mormon Fort, completed in 1855 as the first permanent structure in the future city of Las Vegas. Built by Mormon missionaries led by William Bringhurst near the Las Vegas Springs, it served travelers on the Spanish Trail and the route between Salt Lake City and Los Angeles while supporting missionary work. Though called a fort, it was originally a protective adobe settlement rather than a military post. After abandonment during the Utah War, the site passed through ranching and railroad ownership before preservation efforts secured it. Today it provides a rare direct link between modern Las Vegas and its pre-railroad origins.