Fascinating early geological map of America's oldest national park, from the survey which helped establish its importance. Published in 1879 by Ferdinand Hayden, the map shows the region around Yellowstone Lake, focusing on the surficial geology of the area.
Extremely detailed in its execution, the work of the Hayden survey is clearly visible on the present map. The vast majority of the area is covered with lava flows and other deposits, with only the occasional sedimentary layer visible. Even on Yellowstone Lake, depth soundings are visible.
The geology of this area is, of course, all-important given that one of the world's largest volcanoes lies dormant under Yellowstone Caldera - a fact which was unknown at the time but would slowly be uncovered over the next century.
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 shown in the presented map 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.