This is the general index map from Clarence King's Fortieth Parallel survey. Drawn on a scale of 60 miles per inch, it shows the region to the west of the 102nd meridian. Includes very detailed topography depicted through brushwork. Red overprinting identifies 5 areas where more detailed maps are provided in the atlas. Dissected and remounted on heavy tissue with later, brown marbled end boards with paper labels. The folding format and end boards suggest that this example was once used as a field map. An important map seldom offered outside of the atlas.

References: Wheat (TMW) #1270.

Condition: B+

Light toning and a few minor spots of foxing. Issued folding, dissected, and re-backed with heavy tissue.