It was an army expedition: twenty-three enlisted men, a hunter, a squad of boatmen, Captain Clark's black servant York, and a squad of other soldiers for an escort part of the way. In all, forty-three, under the two captains. Their orders were, to ascend the Missouri River to its head; and, if possible, to cross the mountains and travel westward still, to the Columbia River and its mouth at the Pacific Ocean of the Oregon country. No white man knew what lay before them, for no white man ever had made the trip. The trail was a trail in the dark. This fall they had gone safely as far as the hewn-timber towns of the Mandan Indians, in central North Dakota; here they wintered, and met the little Bird-woman. Her Indian name was Sa-ca-ga-we-a, from two Minnetaree words meaning "bird" and "woman." But she was not a Minnetaree, who were a division of the Sioux nation, living in North Dakota near the Mandans. She was a Sho-sho-ni, or Snake, woman, from the distant Rocky Mountains, and had been captured by the Minnetarees. Between the Minnetarees of the plains and the Snakes of the mountains there was always war. Now at only sixteen years of age she was the wife of Toussaint Chaboneau, a leather-faced, leather-clad French-Canadian trader living with the Mandans. He had bought her from the Minnetarees--and how much he paid in trade is not stated, but she was the daughter of a chief and rated a good squaw. Toussaint had another wife; he needed a younger one. Therefore he bought Sacagawea, to mend his moccasins and greet him with a smile for his heart and warm water for his tired feet. His old wife had grown rather cross and grunty. Chaboneau was engaged as interpreter, this winter, and moved over to the white camp. Sacagawea proved to be such a cheerful, willing little woman that the captains and the men made much of her. And when, in February, a tiny boy arrived to her and Toussaint, there was much delight. A baby in the camp helped to break the long dull spell of forty-below-zero weather, when two suns shone feebly through the ice-crystaled air. A thousand miles it was, yet, to the Rocky or Shining Mountains, by the river trail. In the Mandan towns, and in the American camp, Sacagawea was the only person who ever had been as far as those mountains. They were the home of her people, but nearly three years had passed since she had been taken captive by the Minnetarees. Could she still speak the Snake tongue? Certainly! Did she remember the trail to the country of the Snakes? Yes! Was there a way across the mountains? Yes! Beyond some great falls in the Missouri there was a gate, by which the Shoshonis came out of the mountains to hunt the buffalo on the plains. It was there that she had been captured by the Minnetarees. Would the Snakes be friendly to the white men? Yes, unless they were frightened by the white men. Would she like to go back to her own people? Yes! Yes!