In the record of the Whipple expedition of 1853-4, is found evidence of Mormon influence already material in the Southwest. Whipple thought highly of the agricultural possibilities of the valley of the Colorado River, above the mouth of Bill Williams' Fork and wrote, "The Mormons made a great mistake in not occupying the valley of the Colorado." This Whipple expedition made a painful journey from the Colorado across the Mohave desert and, on March 13, 1854, struck what even then was known as the Mormon Road. The next day Whipple met a party of Mormons en route to Salt Lake. He told them of the murder of one of his Mexican herders by the Paiutes, but the travelers expressed no fear. They said they were at peace with the Indians, a statement over which Whipple expressed surprise. About the earliest American occupation of the southern Nevada point available in the records upon which this office has worked, appears to have been the detail by Brigham Young in 1854 of a party of thirty young men "to go to Las Vegas, build a fort there to protect immigrants and the United States mail from the Indians, and to teach the latter how to raise corn, wheat, potatoes, squash and melons." The missionary party arrived at Las Vegas June 14, 1855. Four days later was started construction of an adobe fort on the California, road, on an eminence overlooking the valley. This fort, 150 feet square, had walls, upon a stone foundation, fourteen feet high, with bastions on the southeast and northwest corners. Gates were not procured until the following year. Houses were built against the inside of the wall and lots were drawn to decide just where each of the brethren should erect his dwelling. There was a garden plot, just below, on the creek, and small farms were provided nearby. Inside the fort was a schoolhouse, in which meetings also were held, this indicating that families soon followed the pioneer missionaries. It is told that "the gospel was preached and that many Indians were converted and baptized." One of these missionaries was Benjamin Cluff, who in later years became a prominent member of the Gila Valley settlements in Arizona. In his biography is found notation that the Las Vegas missionaries worked in lead mines, assumed to have been those in the Potosi section. Some of this lead undoubtedly went back to Utah but, happily, was not used at the time of the 1858 invasion. Another notable member was Wm. C. A. Smoot who died in Salt Lake City in the spring of 1920, and who was one of the original Pioneers who reached Salt Lake July 24, 1847. Having been the last of the first pioneer company to enter the valley, it was quite in keeping that he was the last of the company to leave the valley for the celestial shores.