The Three Forks region became known as one of the most dangerous places in the beaver country. All the Upper Missouri River, from the Yellowstone River on, was dangerous by reason of the widely roaming Blackfeet.
Of course, the American trapper and trader did not stay away, on this account. Manuel Lisa and others had formed the Missouri Fur Company, in 1809. In 1822 the Rocky Mountain Fur Company was organized, at St. Louis, and advertised for "one hundred young men to ascend the Missouri River to its source, there to be employed for one, two, or three years," trapping.
It proved to be a famous company. It had on its rolls Jim Bridger, Kit Carson, Jedediah Smith the Knight in Buckskin, the Sublette brothers, Jim Beckwourth the French mulatto who lived with the Crows as chief, and scores of others, mainly young men, genuine Americans of both French and Anglo-Saxon blood. Its career did not cease until the summer of 1834.
The two men who organized the company were General William Henry Ashley of the Missouri militia, and first lieutenant-governor of the State; and Major Andrew Henry who had helped to found the Missouri Fur Company and now was mining for lead in Washington County southwest of St. Louis.
Major Henry already had served in the Blackfeet country. He was there at the Three Forks in the spring of 1810, when five trappers had been killed or captured and John Colter had decided to pull out. Next, George Drouillard, who had been a hunter with the Lewis and Clark party (another of John Colter's old companions), and whose father Pierre Drouillard had rescued Simon Kenton from the Shawnees, was killed while fighting bravely. Finally the Blackfeet had driven all the trappers from that region. Major Henry led his remaining men west across the mountains, to the Snake River in Idaho. There on Henry Fork he built a trading-post. It was the first American post west of the Rocky Mountains.
Major Henry returned to St. Louis in 1811. He had met with bad luck in the fur-hunt business, so he went into mining. But the beaver country kept calling to him. He was not yet beaten by the Indians, the snows, the freshets and the hunger.
Therefore in 1822 he started again, for the mouth of the Yellowstone and the Great Falls of the Missouri, farther up. The Assiniboines stole all his horses. He stayed at the mouth of the Yellowstone until he had traded for more, from the Crows; went on to the Great Falls—and the Blackfeet again smashed him and sent him back down-river, minus four good men.
General Ashley was to follow him, with reinforcements of another one hundred young men. He was met by a courier from his partner, asking for horses, horses, horses. He stopped to trade with the Arikaras, in present South Dakota; they suddenly attacked him, rolled him up, and stopped him completely.
He had to drop back, fortify, and call for volunteers to take word to Major Henry that nothing could be done this season until the way had been opened. Jedediah Smith, aged twenty-five, stepped forward. He was of New York State, and had been in the West only two years; had never been farther from St. Louis than this, into the Indian country. But his voice rang true; he wished to learn. General Ashley gave him a French-Canadian of St. Louis as a scout companion, and together they crossed the six hundred miles of vast lonely plains infested by the Arikaras and Sioux and Assiniboines, to Major Henry at the mouth of the Yellowstone.
Major Henry's party returned with them, to General Ashley at the mouth of the Cheyenne River in South Dakota. From the United States post at the Lewis and Clark's Council Bluffs, western Iowa of to-day, Lieutenant-Colonel Henry Leavenworth (Fort Leavenworth of Kansas is named for him) of the Sixth United States Infantry, hastened up with six companies of regulars, several cannon and three keel-boats. Joshua Pilcher, president of the Missouri Fur Company, joined him; General Ashley and Major Henry met him with other men; four or five hundred Sioux enlisted—the Sioux hated the Arikaras. And all together (except that the Sioux soon quit, disgusted with the way the white soldiers fought) they battered at the Arikara village from a distance until the enemy announced that it was time to make peace.