During the summer of 1875, Henry Newton, Walter P. Jenny along with 400 men from the US Geographical and Geological Survey led an expedition to explore, describe and map the geology of the Black Hills. This remarkable view (from south to north), helped illustrate how the Black Hills may look from the air, if void of vegetation. Newton's imaginative perspective helps exemplify the Black Hills as one of the most unique geological features in North America.
Map from Topographical and Geological Atlas of the Black Hills of Dakota to accompany the report of Henry Newton, E.M., assistant geologist, published in 1879. Exploration atlas produced for United States Geographical and Geological Survey of the Rocky Mountain Region.