CONTENTS, 
PAGE 
Historical Introduction, .......... 1 
PART I. 
Descriptive Geology of tiie Routes. 
CHAPTER I.—Exploration of Platte River Valley from Bellevue to tlic mouth of the Elkhorn River, . 5 
CHAPTER II.—From Bellevue to the Big Sioux River, ...... 8 
CHAPTER III.—From Omaha City to Fort Laramie, ...... 11 
CHAPTER IV.—Geology in the Vicinity of Fort Laramie, ..... 15 
CHAPTER V.—Fort Laramie to the Black Hills, ....... 17 
CHAPTER VI.—From Bear Peak to Fort Randall on the Missouri River, ... 29 
PART II. 
General Geology of the Country. 
CHAPTER VII.—Granite, Stratified, Azoic, and Eruptive Rocks, ..... 33 
CHAPTER VIII.—Potsdam Sandstone (Lower Silurian), ..... 36 
CHAPTER IX.—Carboniferous and Permian Rocks, ....... 38 
CHAPTER X.—Jurassic System, ........ 67 
CHAPTER XI.—Tertiary Basins of the Upper Missouri, ...... 92 
CHAPTER XII.—Quaternary Deposits, ........ 107 
CHAPTER XIII.—Resume of the Geology of the Upper Missouri and its Tributaries, . . 114 
CHAPTER XIV.—Minerals and Geological Specimens, ...... 131 
PART III. 
Zoology and Botany. 
CHAPTER XV.—Mammals, .......... 138 
CHAPTER XVI.—Birds,.151 
CHAPTER XVII.—Reptiles, Fishes, and Recent Shells, ...... 177 
CHAPTER XVIII.—Botany,.182 
