which maps have been published. Over 3,300 quadran 
the United brutes have • been surveyed, and maps of I 
. 
similar to the one on the other side of this sheet have 
The topographic map is the base on which the geolog 
mineral resources of a quadrangle are represented, aid 
maps showing these features are bound together with a d 
tive text to form a folio of the Geologic Atlas of the IJ 
° 
States. More than 220 folios have been published. 
Index maps of each State and of Alaska and Hawaii sh 
the areas covered by topographic maps and geologic folios 
lished by the United States Geological Survey may be ob 
free. Copies of the standard topographic maps may be obt 
for 10 cents each; some special maps are sold at different r 
I 
A discount of 40 per cent is allowed on an order for 
amounting to $5 or more at the retail price. The 
folios are sold for 25 cents or more each, the price 
on the size of the folio. A circu lar describing the folio 
nt on request. 
Applications for maps or folios should be accompany 
cash, draft, or money order (not postage stamps) and sho 
addressed to 
THE DIRECTOR, 
United States Geological Surv< 
\on, 
September, 1928. 
