"Excursions in the United States Guidebooks 1 to 30", U.S. Geological Survey (USGS)

These guides were issued for the U.S. Geological Survey in connection with the 16th International Geological Congress held in 1933. They contain over 300 plates, more than half of which are folding, and over 400 text illustrations. They cover the entire lower 48 states by geological regions, usually in terms of specific tours along local highways or railroads. Some subjects include: Baltimore and Ohio Railroad, The Salt Lake City region, Middle California and Western Nevada, Northern Virginia, Southern Maryland, Oklahoma, and Texas. Two slipcases holding 30 guidebooks in wraps, printed label on each case provides contents.

References:

Condition: B

Slipcases soiled, with pencil marks, frayed and rubbed corners. Pamphlets overall good, with some staining and a little wear.