GEOLOGICAL SURVEY BULLETIN 1493
UNITED STATES DEPARTMENT OF THE INTERIOR
CECIL D. ANDRUS, _Secretary_
GEOLOGICAL SURVEY
H. William Menard, _Director_
[Illustration: U. S. DEPARTMENT OF THE INTERIOR · March 3, 1849]
The Geologic Story of the Great Plains A nontechnical description of the origin and evolution of the landscape of the Great Plains · 第 2 / 32 题