Lieut. Fremont had instructions to explore and report upon the country lying between the frontiers of Missouri and the South Pass in the Rocky Mountains, on the line of the Kansas and Great Platte Rivers, and with his party, leaving St. Louis on the 22nd of May, 1842, by steamboat for Chouteau's Landing on the Missouri, near the mouth of the Kansas, at a point twelve miles beyond at Chouteau's trading post, he encamped there to complete his arrangements for this important expedition. CHAPTER XVI. Fremont was delayed several days at Chouteau's Landing, by the state of the weather, which prevented the necessary astronomical observations, but finally all his arrangements being completed, and the weather permitting, the party started in the highest spirit, and filled with anticipations of an exciting and adventurous journey. He had collected in the neighborhood of St. Louis twenty-one men, principally Creole and Canadian _voyageurs_, who had become familiar with prairie life in the service of the fur companies in the Indian country. Mr. Charles Preuss, a native of Germany, was his assistant in the topographical part of the survey. L. Maxwell, of Kaskaskia, had been engaged as hunter, and Christopher Carson as guide. Mr. Cyprian Chouteau, to whose kindness, during their stay at his house, all were much indebted, accompanied them several miles on their way, until they met an Indian, whom he had engaged to conduct them on the first thirty or forty miles, where he was to consign them to the ocean prairie, which stretched, without interruption, almost to the base of the Rocky Mountains. During the journey, it was the customary practice to encamp an hour or two before sunset, when the carts were disposed so as to form a sort of barricade around a circle some eighty yards in diameter. The tents were pitched, and the horses hobbled and turned loose to graze; and but a few minutes elapsed before the cooks of the messes, of which there were four, were busily engaged in preparing the evening meal. At nightfall, the horses, mules, and oxen, were driven in and picketed--that is, secured by a halter, of which one end was tied to a small steel-shod picket, and driven into the ground; the halter being twenty or thirty feet long, which enabled them to obtain a little food during the night. When they had reached a part of the country where such a precaution became necessary, the carts being regularly arranged for defending the camp, guard was mounted at eight o'clock, consisting of three men, who were relieved every two hours; the morning watch being horse guard for the day. At daybreak, the camp was roused, the animals turned loose to graze, and breakfast generally over between six and seven o'clock, when they resumed their march, making regularly a halt at noon for one or two hours. Such was usually the order of the day, except when accident of country forced a variation, which, however, happened but rarely.