A colorful map of the United States with terrific detail of the geology. Color code identifies twelve different geological formations. The Pleistocene regions are further divided into Ice work and Water work areas. Fine detail also of hydrology. The majority of the map has been colored, showing in particular the growth in knowledge of the geology of the western U. S.
Folding as issued. Strong color and impression. A trace of what appears to be color offsetting in blank Gulf of Mexico, still very good.