Jackson’s Hole is that part of the Upper Snake River Valley which lies at the eastern base of the Teton Range. One of the largest enclosed valleys in the Rocky Mountains, its glaciated floor extends about sixty miles north and south, and varies up to twelve miles in width. It is bounded on the west by the Tetons, on the east and south by the less pretentious Mount Leidy Highlands and the Gros Ventre and Hoback Mountains. The Gros Ventres merge imperceptibly into the Wind River Mountains farther east, the crest of which forms the Continental Divide. The southern extremity of the Tetons merges with the eastern end of the Snake River Range near the canyon where the Snake River escapes from the valley. Historic Jackson’s Hole, also known as “Jackson’s Big Hole”—but now politely refined to just plain Jackson Hole—was named in 1829 for David Jackson, one of the partners of the Rocky Mountain Fur Company. To the early trapper a “hole” was a sizeable valley abounding in game, and usually (with the exception of Yellowstone’s “Firehole”) associated with some distinctive personality—hence Brown’s Hole, Pierre’s Hole, Gardner’s Hole, etc. However, Jackson’s Hole was more than just a pleasant spot for trapping and camping. Research gives substance to the view that this was the historic crossroads of the Rocky Mountain fur trade. Jackson’s Hole was destined by geography to become a traffic center of the Western fur trade. Between South Pass at the head of the Little Sandy and the northern passes above the Three Forks of the Missouri it offered the most feasible route across the Rocky Mountain barrier. In addition, it was the focal point of a region that was highly prized and vigorously contested because of its populous beaver streams. Here trappers’ trails converged like the spokes of a great wheel and, after Lewis and Clark, most of the important trapper-explorers crossed Jackson’s Hole on their journeys. [Illustration: Indian “Buffalo Jump”—Yellowstone Valley.] In historic times there were seven gateways to and from Jackson’s Hole: northward up Snake River; northeastward up Pacific Creek to Two Ocean Pass; eastward up Buffalo Fork to Twogwotee Pass; eastward up the Gros Ventre to Union Pass; southward up the Hoback to Green River; westward via Teton Pass or Conant Pass (at the south and north extremities of the Teton Range) to Pierre’s Hole. [Illustration: “Dawn of Discovery”—Exhibit in Fur Trade Museum, Grand Teton National Park.]