24 
SURVEY OF THE COLORADO OF THE WEST. 
ness tlie surface exposure of all the great formations extending through- 
out the country which has been surveyed. It is hoped that this can be 
done on a map, the topographic features of which are indicated by con- 
tour lines. The material for such a map has been prepared. 
PALEONTOLOGY. 
I 
While much time has been devoted to the structural geology of the 
country, we have not neglected the paleontology, and we have had such 
success in collecting fossils as to be able to refer all these rocks to the 
grand groups which have been established on a paleontological basis in 
the general geology of North America. At the initial point of our work, 
Green Eiver Station, we have collected a good suite of Tertiary fossils, 
consisting of the remains of vertebrates, insects, mollusks, and plants. 
In the canons along the northern flank of the Uintah Mountains we 
have again collected fossils of Tertiary age, and also of the Cretaceous, 
Jurassic, and Carboniferous ages. 
On the southern slope of the Uintah Mountains a like series was col- 
lected but in reverse order $ in the Jura, especially, we find a great 
variety of forms. Again, in the Canon of Desolation we collected Ter- 
tiary fossils ; in Gray Canon, Cretaceous fossils, and on the river below 
fossils of the Jura. In Cataract Canon we succeeded in making a large 
collection of the remains of Carboniferous age, consisting of fish, 
teeth, shells, and corals. In the Grand Canon of the Colorado, carbon- 
iferous forms were found in abundance. In like manner all of our geo- 
logical sections can be studied with the aid of the fossil remains which 
have been collected. 
ECONOMIC GEOLOGY. 
In much of the area embraced in the survey there are extensive 
beds of coal. We first met with them in descending Green River, about 
eight miles below the railroad crossing, and I note the interesting fact 
that we discovered vertebrate and invertebrate fossils immediately 
overlying the heaviest bed of coal. We again found extensive beds 
outcropping in the upturned edges of the Tertiary rocks on the north- 
ern flank of the Uintah Mountains ; still other beds are found on 
the southern slope of these mountains and in the vfilley of the 
White and the valley of the Uintah. Again a series of beds was 
discovered in Gray Canon. On the headwaters of the Price and 
San Rafael Rivers, or in Castle Valley, beds of great geographical ex- 
tent and great thickness were discovered and we traced them on to 
the south by the headwaters of the Dirty Devil, the Escalante, 
the Paria, the Kanab, and the Rio Virgen, and then to the north 
on the western escarpment of the Pauiis-a-gunt Plateau. All of these 
coal-beds have been carefully studied, so as to determine as far as possi- 
ble their geographic extent, their thickness and their geological relations ; 
and this survey has revealed the important fact that a great district of 
