After founding Salt Lake City in 1847, the Mormon Church expanded its settlement westward. The Las Vegas Mission was established in June 1855 as an outpost roughly halfway between Salt Lake City and Southern California. Built alongside the Las Vegas Creek, 30 missionaries constructed a 150 square foot adobe fort. This was the first non-native building and settlement in the Las Vegas Valley. A part of an original 1855 wall remains and is the oldest extant building remnant in Nevada. The Mormons taught new farming techniques and religion to the local Paiutes. Lead was discovered in the nearby mountain, but the mining effort proved unseccessful. By 1857 the Mission was abandoned because of dissention among the leaders, the summer climate and a deteriorating relationship with the Paiutes. In 1865, Octabius D. Gass developed a ranch on the site and proveded food for travelers and nearby mining communities. By 1881, the property passed to Archibald and Helen J. Stewart. Although Archibald was killed in a gunfight in 1884, Helen continued to operated the ranch, raising their five children and providing rest and comfort for travelers. In 1902 she sold the ranch, the surrounding land and the water rights to the San Pedro, Los Angeles and Salt Lake Railroad. On her former land in 1905, the new town of Las Vegas was born. In 1972 the Old Fort was placed on the National Register of Historic Places. The site is now part of the Nevada State Park System.