In the spring of 1810, after Colter had departed, the Missouri Fur Company fort at Three Forks was so besieged by the Blackfeet that Andrew Henry was forced to flee with his trappers southwestward. They crossed the Continental Divide to the north fork of Snake River, since known as Henry’s Fork. A few log shelters built here near present St. Anthony, Idaho, called “Henry’s Fort,” became the first American establishment on the Pacific slope. During the rigorous winter of 1810-1811 it may be reasoned that these men explored the country within a wide radius of the Teton Mountains. Any belief that they touched Yellowstone Park must be conjectural, but that they were acquainted with Jackson’s Hole is quite evident from the testimony of the Astorians. In the spring of 1811 the starving company disbanded. Henry and others returned down the Missouri via Three Forks, while John Hoback, John Robinson and Jacob Reznor went eastward via Teton Pass, Jackson’s Hole, Twogwotee Pass, and overland to the Arikara villages on the Missouri, where they shaped a dugout and proceeded downstream. In 1808 John Jacob Astor secured a charter from the state of New York creating the American Fur Company. The most ambitious of his schemes was the establishment of a trading post at the mouth of the Columbia River, to exploit the wealth of the Northwestern wilderness. To promote this enterprise, Astor organized the subsidiary Pacific Fur Company and sent out two expeditions, one of which went by sea around Cape Horn, while the other was to proceed overland along the route of Lewis and Clark. The overland Astorians achieved fame as the first transcontinental expedition after Lewis and Clark, but fate decreed that they should blaze their own trail—through Jackson’s Hole. Early in 1811 the overland party, under the command of Wilson Price Hunt of New Jersey, left St. Louis and sailed by keelboat up the Missouri River. On May 26, near the mouth of the Niobrara River, they met Hoback, Robinson, and Reznor. This trio was persuaded to join the outfit as guides and hunters, and it appears that it was their reports of hostile Indians on the Upper Missouri that prompted Hunt to abandon his boats on July 18 at the Arikara villages and proceed on dry land. From this point on the expedition consisted of 82 horses, 62 men, and the squaw and two children belonging to the interpreter Pierre Dorion. [Illustration: Fort Astoria.] The hopeful caravan retraced the route that Hoback and his companions had followed across the trackless plains and the Bighorn Mountains, then started up Wind River. Here, on September 14, according to Irving’s Astoria, the guides