Spring opened early, and on April 7, 1805, Fort Mandan was abandoned, one party of ten with the barge going down the river with despatches and specimens. Lewis and Clark with their party of thirty started up the Missouri in six canoes and two large open boats, which had been constructed by them. They had three interpreters--Drewyer, Chaboneau, and his wife. Drewyer was a Canadian half-breed who had always lived in the woods, and while he had inherited from his mother the intuitive sagacity of the Indian in following the faintest trail, he had also acquired to a wonderful degree that knowledge of the shifts and expedients of camp life which is the resource and pride of the frontier huntsman. Chaboneau's life had been largely spent among the Blackfeet, by whom his wife, a Snake Indian, had been taken in war and enslaved when a young girl. At the mouth of the Little Missouri the three French hunters, who had ventured to follow the party, stopped for trapping, as they found beaver very plentiful. Chaboneau Creek, the farthest point on the Missouri yet visited by white men, was passed, and on April 26th they arrived at the mouth of the Yellowstone. Lewis was here particularly pleased with the wide plains, interspersed with forests of various trees, and expressed his opinion that the situation was most suitable for a trading establishment. Spring had now fairly opened, the trees were in leaf, a flower was seen, and despite the scanty verdure of the new grass, game was very abundant. In many places, however, the barren banks and sand-bars were covered with a white incrustation of alkali salts, looking like frost or newly fallen snow, which were present in such quantities that all the small tributaries of the Missouri proved to be bitter and unhealthy water. Signs of human life became rarer, but now and then they passed an old Indian camp, and near one saw the burial place of an Indian woman. The body, carefully wrapped in dressed buffalo robes, rested on a high scaffold, with two sleds and harness over it. Nearby lay the remains of a dog sacrificed to the shades of his dead mistress. In a bag were articles fitting for women--moccasins, red and blue paint, beavers' nails, scrapers for dressing hides, dried roots, a little Mandan tobacco, and several plaits of sweet-smelling grass. The oar was plied unceasingly save when a favoring wind filled their sails and facilitated their progress. In early May they drew up their canoes for the night at the mouth of a bold, beautiful stream, and in the abundant timber found feeding on the young willows so many clumsy porcupines that they called it Porcupine River. Game was present in vast quantities; the elk were tame, and the male buffalo would scarcely quit grazing at the approach of man. As Lewis remarks: "It has become an amusement to supply the party with provisions."