104 United States Survey of the Territories. [February, a 
parative examinations of the Mesozoic and Cenozoic formations 
in Middle park he proceeded westward to the headwaters of the 
Yampa river, following that stream down to the western foot-hills 
of the Park range of mountains. 
Here resuming his comparative examinations of the Mesozoic 
and Cenozoic strata, he passed down the valley of the Yampa as 
far as Yampa mountain, one of those peculiar and remarkable up- 
thrusts of Palaeozoic rocks through Mesozoic strata. In all this 
area, as well as that between the Yampa and White rivers, the 
Laramie group reaches a very great and characteristic develop- 
ment, and it received careful investigation, yielding some of the 
most important results of the season’s work. Crossing the 
ground between the two rivers named to White River Indian 
agency, thence down White River valley about one hundred 
miles; thence to Green river, crossing it at the southern base of 
the Uintah mountains, making many detours on the way, he : 
reviewed the geology of the region which he had surveyed 
during the previous season. This review brought out not only — 
the important paleontological facts before referred to, but it also i 
added materially to the elucidation of the geological structure of — 
the region which lies between the eastern end of the Uintah a 
mountain range on the west and the Park range on the east. 
Beyond Green river he pursued his travels westward, studying 
logical and paleontological characteristics. 
In this way he traversed the whole length of the Uintah range, 
crossing at its junction with the Wasatch range over into the val- 
ley of Great Salt lake. Recrossing the Wasatch to the north 
side of the Uintah range he continued his examinations of the 
Cretaceous and Tertiary strata into and entirely across the great 
Green River basin, leaving the field at the close of the season 
Rawlins station on the Union Pacific railroad. j 
A general statement of the results of the season’s work h 
been given in a previous paragraph, but the following additional 
summary will make the statement somewhat clearer, being mas ; 
after the route of the season’s travel had been indicated. The 
formations of later Mesozoic and earlier Cenozoic ages, especiall 
those to which Dr. White in former publications, has applied the 
provisional designation of “Post-Cretaceous,” have received pat 
