ee 
Charles D. and Mary Waux Walcott Research Fund 
GEOLOGY AND VERTEBRATE PALEONTOLOGY 
OF UPPER EOCENE STRATA IN THE 
NORTHEASTERN, PART OF} TELE 
WIND RIVER BASIN, WYOMING* 
PART) 1.) GEOLOGY ? 
By HARRY A. TOURTELOT 
Geologist 
United States Geological Survey 
(WITH I PLATE) 
INTRODUCTION 
GENERAL SETTING OF THE AREA 
The northeastern part of the Wind River Basin described in this 
report includes the lower lands of the basin and parts of the border- 
ing mountain ranges, which are the eastern part of the Owl Creek 
Mountains and the southern end of the Big Horn Mountains in Hot 
Springs, Fremont, and Natrona Counties, Wyoming (figs. 1 and 2). 
Lost Cabin and Lysite are the only towns within the area. Lysite is 
a station on the Chicago, Burlington, and Quincy Railroad and is 
about 8 miles north of Moneta, a town on U. S. Highway 20. 
The Owl Creek and Big Horn Mountains are folded and faulted 
mountain ranges arranged in echelon and made up of pre-Cambrian 
and Paleozoic rocks with minor amounts of Mesozoic rocks along the 
outer flanks. The bordering part of the Wind River Basin is under- 
lain by Tertiary strata of both early and late Eocene age. The younger 
Eocene strata consist of resedimented andesitic volcanic rocks and 
form a narrow belt adjacent to the mountains, and in part within 
them. These volcanic-rich strata are separated from the Wind River 
1 Part 2 of this paper, “The Mammalian Fauna of the Badwater Area,” by 
C. Lewis Gazin, appeared in Smithsonian Misc. Coll., vol. 131, No. 8, Oct. 30, 
1956. 
2 Publication authorized by the Director, U. S. Geological Survey. 
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 134, NO. 4 
