its turbulent waters, snags, and sand bars made navigation difficult; flies and mosquitoes, those pests of bottom and marshy land, were abundant. They had some trouble with the Sioux Indians, but Captains Lewis and Clark were evidently able to cope with them successfully. They reached a point near the present site of Bismarck, N.D., that summer. This region was occupied by the Mandan Indians, who lived in villages of rather permanent character. Among these they found some who had traveled far toward the headwaters of the Missouri. One woman, known as the Bird Woman, was especially helpful to them. She had been captured some time previously from a mountain tribe and according to Indian custom married to one of their own number, a half breed. During the stay at winter quarters, in addition to writing up their journals and records very carefully, they cultivated the acquaintance of this woman. She, with her half breed husband and small child, accompanied the expedition when it began its onward journey in the spring of 1805. There was real need for them not only to act as guides and interpreters, but to replace those who had been sent back down the river with reports of the progress and observations of the expedition up to this time. Part of the duties of the expedition, as heretofore intimated, was to note the character and productivity of the land, as well as the nature and number of Indians found and general information concerning them and their mode of living. When the falls of the Missouri were reached there seemed to be an _impasse_. But from logs and other timbers found there they constructed a crude wagon on which their supplies and equipment were transported to the river above. They had brought with them the iron framework of a smaller boat than those used heretofore with the idea of covering it with stretched skins. They found difficulty, however, in getting it watertight. They attempted to get pitch by heating pine tree trunks but were again unsuccessful. They resorted finally to a combination of powdered charcoal, beeswax, and buffalo tallow--practically natural products of the land. The boat floated nicely and they were greatly encouraged but when it was taken from the water the mixture dropped off and the seams opened up. Lewis finally gave up the attempt and buried the framework and built canoes according to the Indian fashion. In passing up they came to forks in the river and were often at a loss which to take. By conference with the Indian woman and reports of scouts sent ahead they were usually fortunate in choosing the right course. Being explorers of a new country they assigned names to the rivers as they discovered them. At three forks, they called the rivers, Gallatin, Madison, and Jefferson, names which they still retain. Three branches of the Jefferson were Philosophy, Philanthropy, and Wisdom; these names have not remained--probably they were too fanciful--the Philanthropy is now the odoriferous Stinking Water.