"Something seems to tell me he will do it," added Roger, "and so I have decided not to let it worry me any longer. We will keep Lascelles and his son here for some weeks, so that they will be powerless to catch up with Mayhew, even if they wished to try it. And Beaver Tail seemed greatly pleased with the generous way Captain Lewis treated him, too, so we have made good friends of the Sioux." "He gave the chief a gun and some ammunition," remarked Dick. "He was as pleased with it as a child would be with a new toy. And every brave also received something to show that we wanted them to be our friends. But the dinner we gave them did not seem to reach the right spot. I saw more than one slyly throw the tea away when they thought no one was looking." "They will stick to roast dog as a feast dish," laughed Roger. "I was afraid at one time there might be trouble between the Mandans and the Sioux, for they are old rivals of the chase and the warpath. But Captain Lewis managed to patch up a truce that may last while we are here, at any rate, even if the old warfare breaks out again afterwards." "It took a good deal of talk, though," suggested Roger, "to induce the Mandans to hide those old Sioux scalps they had swinging about their teepees. If the braves of Running Elk had glimpsed those nothing could have kept them from making trouble. But it is simply wonderful what power Captain Lewis has over men." "If we ever do set eyes on the great ocean that lies far beyond the range of rocky mountains," Dick affirmed, "it will be owing mostly to the cleverness of the President's private secretary." History has recorded the facts, and the young pioneer in stating his opinion was only saying what other men have conceded. A few days after Mayhew left the camp, well provisioned and armed for his dangerous trip over the back trail, winter set in in earnest. The boys were well satisfied to be so comfortably housed and among friends, instead of wandering amidst those strange scenes of which they never seemed to tire of talking, where the earth appeared to be on fire deep down under the outer crust, and continually spouted those colossal streams of steaming water. The four Frenchmen were kept prisoners until several weeks had elapsed, and then allowed to go. They had a _cache_ somewhere, they admitted, with an abundance of ammunition as well as other supplies, so there was little fear of their perishing in the severity of the winter weather. As the days and weeks drifted along Dick and Roger carried out many of their little plans. They hunted when the weather admitted, and accompanied Jasper Williams on trapping jaunts that covered several days. They also had intercourse with the peculiar Mandan Indians, and learned a multitude of interesting things connected with the tribe called the "White Indians," a race which has always been a mystery to historians.