APPENDIX I. 



REPORT ON THE GEOLOGY 



[By Hknry Enge 



INTRODUCTION. 



Washington, D. C, July 19, 1860. 



Sir: I herewith submit to you my report on the geology of the country traversed 

 by the expedition under your command in 1858 and 1859, from Fort Leavenworth, 

 Kansas, to the Sierra Nevada, near Carson Valley. Only little has been known, hereto- 

 fore, of the geology of this whole country, except of its eastern portion, and even there 

 important questions remain unsettled, while the western portion has been altogether a 

 terra incognita. By your expedition, therefore, important additions have been made to 

 our knowledge of the geological structure of the central portions of the continent. 



Some additional observations have been made in regard to the Upper Carboniferous 

 and more recent formations of Northeastern Kansas. In the remarkable bluff forma- 

 tions of the North Fork of Platte River, below Fort Laramie, mammalian and chelo- 

 nian remains have been discovered, which indicate their analogy with the interesting 

 deposits of the Bad Lands of White River, famous for the abundance of their terres- 

 trial pre-adamitic fauna; and the general character and succession of the Tertiary strata 

 have been investigated, from the most recent to the oldest, along Platte River, and farther 

 on across the South Pass to the Walisateh M< mntains. The existence of Jurassic strata 

 in the territory of the United States, which had been very problematical till within a 

 short time, when they were first recognized in the Black Hills, by Mr. Meek and Dr. 

 Hayden, on Lieutenant Warren's expedition, has been fully established, and they have 



been recognized at various points i 



rkvM.mim.h.s near North Pla 



i the eastern slope of the Wahsatch range. The Triassic and < Iretaceous Epochs have 

 also been found represented. In the Green River Valley a Tertiary fivsle water forma- 

 tion has been discovered, and in the Wahsatch Mountains an estuary, possibly Eocene 

 Tertiary, deposit. Sandstone and coal formations of apparently Cretaceous age have 

 been observed, considerably developed in that range. 



The extensive distribution of coal, partly of very superior quality, from the eastern 

 part of the Rocky Mountains to the Salt Lake country, has been more fully demon- 

 strated, and is of paramount practical importance, bearing upon the question ot the 

 best location of a railroad to the Pacific coast. 



