The decades that followed are frequently referred to as the “Fur Trade Era,” for then Jackson Hole was a veritable crossroads of the Rocky Mountain fur trade and the scene of intensive exploration and trapping activities by both British and American fur interests. Explorations by such “mountain men” as Robert Stuart, Jedediah Smith, Jim Bridger, and Kit Carson helped to insure the acquisition of “Oregon Territory” for the United States. The picturesque name of “Jackson Hole” for this high mountain valley dates back to 1829, when Capt. William Sublette named it for his fellow trapper and partner, David E. Jackson, when he found him in camp on the shore of “Jackson’s Lake” after the Wind River rendezvous of 1829. The Rocky Mountain fur trade declined sharply after 1839, and during the period of the great migrations to Oregon, California, and Utah in the 1840’s and 1850’s via South Pass, the Jackson Hole country was largely deserted. There were brief flurries of interest in 1860, when Jim Bridger guided the Raynolds’ expedition through Jackson Hole, and in 1863, when Montana prospectors searched the gravel bars of Snake River for gold. In the period from 1872 to 1880 several Government expeditions explored the valley and named most of the geological features of the surrounding country. Thomas Moran, the famous artist, and William H. Jackson, the “Pioneer Photographer,” painted and photographed the Tetons during some of these expeditions. The first settlers came to Jackson Hole in 1884, and began building homes at what later became the villages of Jackson, Moran, and Wilson. During these days of early settlement Jackson Hole acquired a reputation as the hideout of many of the outlaws of the West. No doubt some did use this secluded valley as a hideaway, but undoubtedly these stories were exaggerated, as Jackson Hole sometimes is confused with the “Hole in the Wall” and other known sanctuaries of Wyoming “bad men.” Sculpture of the Landscape Geologists regard the Teton Range as one of the most impressive known ranges of the “fault block” type. Ages ago, along a great break in the earth’s crust (the “Teton Fault”) a gigantic block was uplifted and given a westward slant. Long-continued sculpturing of this tilted fault block by many natural agencies—frost, streams, avalanches of rock and snow, and glaciers—has produced the notable scenic features of the Teton Range as we now see it. [Illustration: —UNION PACIFIC RAILROAD PHOTO _Mount Teewinot as seen from the Jenny Lake Museum._] Streams on the east slope, having steeper gradients and therefore more rapid flow than the other streams, cut spectacular canyons on this side of the range. As these streams have worked back into the giant block, they have caused the divide to migrate westward, diverting more and more drainage to the east and leaving the great peaks standing like monuments on the ever-widening east slope.