Jackson Hole to Bear Lake.
Fantastic visual representation of the geology in the area between Utah, Wyoming, and Idaho, made by one of the great government surveys of the American West. This map was produced by Ferdinand Hayden and his colleagues in 1879, based on data gathered in the late 1860s and the 1870s.
The map is remarkable for its early detail, particularly in the region around "Jackon's" Hole, with Jackson Lake, Jenny's Lake, the Gros Ventre River, Taggart's Lake, and a number of peaks named. Eastwards, the map stretches to the Rattlesnake Hills, while it reaches the Cache Valley and the Bear River Range in Utah in the west.
The geological information shown on this map is fantastically detailed given the tools at the disposal of the Hayden Survey. In the west of the map, the high mountain peaks of the Tetons and of the northern Basin and Range province are represented by densely-packed northward striking successions of units. In the southeast, volcanic plugs and other erupted rocks are seen in the vicinity of pilot butte. The ages of rocks shown span from Quaternary to Silurian.
The Hayden Survey -- The Greatest of the Four Great Surveys
The late 1860s and early 1870s saw four great surveys of the American West: the King Survey, which mapped the region around the 40th parallel; the Wheeler Survey, which attempted (unsuccessfully) to map the whole of the territories and western states at a moderate scale; the Powell Survey, which focused on the southwest and the Grand Canyon region; and finally the Hayden survey, which surveyed the territory of Colorado as well as the last great unmapped region of the Lower Forty-Eight: the Yellowstone Basin.
The Hayden Survey's most prolific years were 1871-72, which were dedicated to northwestern Wyoming. Up until then, the Yellowstone had been briefly explored by two previous surveys, including the Folsom-Cook and the Washburn-Langford-Doane expeditions of 1869 and 1870 respectively. However, these surveys lacked the resources of the Hayden Surveys: full government support, tens of thousands of dollars, and over sixty men. The Hayden Survey relentlessly worked on the territory, and its reports--most notably in the photos published which were taken by William H. Jackson--were the reason why the senate approved Yellowstone as the nation's first national park in 1871.
The area around Jackson Hole was surveyed primarily in the summer of 1872. In that year, the expedition split up between a group dedicated to the Yellowstone, led by Hayden, and one dedicated to the Snake River area, led by James Stevenson. The latter group primarily spent the majority of the summer focused on the Tetons and Jackson's Hole. During this part of the survey, William Jackson took the first photos of the Tetons, and James Stevenson and his colleague N. P. Langford became the first Anglo-Americans to climb Grand Teton.
The Hayden Survey would return to the Jackson Hole area in 1877 and 1878, however, the bulk of the mapping had been conducted in 1872. 1878 was the final field year for all the four great surveys, after which the federal government, wary of the often conflicting politics of the parties, founded the USGS to consolidate the surveying exercise. These Great Surveys represented the last triumph of the age of discovery in the American West.