Spectacular geological map of the region, colored based upon the mineralogical content of the region. The map is dissected horizonally by the Old Spanish Trail. Pagosa Peak, Pagosas Springs and San Juan City appear on the eastern side of the map. Pinon Mesa appears at the southcentral part of the map, with several ruins and a Ruined Pueblo noted on the Rio la Plata and Rio De Las Animas. In all, a number of ruins are noted on the map. Lone Cone and Sneffes Peak mark the northcentral limits of the map. Silverton appears, along with a modest town grid. Las Animas, Merrit's Ranche and a few other modern settlements are noted, along with Cave Houses and a number of towers and other Indian houses and ruins on the Rio Manca and Rio San Juan. The southern extremity of the Old Spanish Trail shows a split in the road, one being the Wagon Road, one being the trail. In 1869 Hayden was given a large appropriation and made head of the United States Geological Survey of the Territories. The biggest and best-known of the Great Surveys. The primary purpose of the expeditions to the Rocky Mountains was to evaluate the geological and mineral content of the regions. In addition to his interest in western minerals, Hayden was also one of the first to see the West as the land of the nature-loving tourist. In 1871 Hayden made an expedition into the Yellowstone Geyser Region resulting in spectacular photographs taken by William H. Jackson. The Yellowstone expedition made Hayden famous, but perhaps his most important was the detailed exploration and mapping of Colorado. Here his teams worked through some of the most rugged country in the West to complete the masterful Atlas of Colorado.