Marcou's report contains one of the earliest geologic maps of the entire contiguous United States entitled Carte Geologique des Etats-Unis et des Provinces Anglaises de l'Amerique du Nord (23 x 16.3"). This colorful map shows the United States and the Baja and identifies twelve different geological types by color. Along the top is a color geological profile of the region from Ft. Smith to Los Angeles along the route taken by Whipple’s expedition during the Pacific Railroad survey. Copper trap is still shown for the southeast trending Wind River Mountains (as in 1853), a cartographic error that would persist on some maps for the next year or so (Blevins). The report also contains the first geologic map of New Mexico (26.7 x 5.7"), and a reproduction of William Maclure's geologic map of the US (7.5 x 9.0").

Ex-library, small folio, vi, [2], 144 pages with 9 tinted plates, 3 folding color folding geologic maps, and 1 woodcut. An additional 1855 French language Marcou paper from the French Academy of Sciences has been bound in at rear. Rebound in pebbled green cloth over green marbled boards with old handwritten paper label at top of spine. Very scarce.

References: Marcou #49.

Condition: B+

The folding map is very good with light toning, a very short binding tear at right that just passes the border, and a library stamp in the image at lower left. The two smaller maps and plates are also very good with light scattered foxing. Text is mostly clean and bright with some scattered foxing in the last 20 pages or so. The folding map, title page, front free-endpaper, and front pastedown have old library stamps. Light wear to the extremities with some sunning at the top of the front board.