ROUTE NEAR THE FORTY-FIRST AND FORTY-SECOND PARALLELS. 67 
plains sloping east and west. A few miles to the north of it commences the elevated range 
called the Wind River chain, (a portion of the Rocky mountains,) while an extensive table- 
land, dotted here and there with isolated hills, stretches away to the south. This elevated 
plateau is in latitude 42° north, and, viewed as a whole, may be said to extend east and west 
from the Black Hills to the Bear mountains; and from the Wind River mountains and 
Black Hills in the north, to the Park and Uinta mountains in the south, having a length from 
east to west of about 290 miles, and breadth north and south of 100 miles. Its general eleva- 
tion is about 7,500 feet, though in portions it has been reduced to 6,000 feet by the action of 
streams. 
The direction taken by the waters of its surface, divide this great plateau into three dis- 
tinct parts,—one drained by the Laramie river, one by the North fork of the Platte and 
Sweet Water river, and the other by the Green river and other branches of the great Colorado 
of the west. The divides between each of these portions are slight, and such, perhaps, as 
have been produced by the action of the waters alone. Small lake basins exist in several 
parts, which contain only pools of brackish water, proving in themselves the dryness of the 
climate, since the accumulated waters have never been sufficient to force an outlet or form a 
continuous lake. The waters that traverse the other portions come mainly from the mountains. 
The amount of snow that falls is not exactly known, but it must be small; and there is reason 
to think that, probably, the accumulations of the winter will rarely exceed one foot in depth. 
During certain seasons of the year, (the spring,) parts of this plateau are well watered, and 
abound with buffalo and other game. Captain Stansbury saw abundant signs of the buffalo 
having been in immense numbers just west of Bridger’s Pass; but at the time, (September,) 
they had all disappeared in search of water. He also encountered slight rains and fog in this 
vicinity ; but the character of the soil was such as promised fertility, had there been a suf- 
ficiency of moisture, the absence of which is the curse of all this region. Excepting the 
immediate banks of the streams, some of which produce grass and trees of cotton-wood, willow, 
and aspen, it is one vast sage or artemisia desert. All reports concur in giving it this char- 
acter. 
The rocks and soil in the western part are soft and easily crumbled, and, under the action of 
its torrent-like streams during spring freshets, are much abraded and torn away; and the 
debris scattered over the bottoms have, in many cases, destroyed every particle of vegetation, 
and reduced these to the most perfect desolation. 
The valley of the North fork of the Platte is narrow and well timbered with magnificent 
cotton-wood, but west of this Captain Stansbury says he saw nothing deserving the name of 
tree, only a few stunted cedars being found between the Platte and Green rivers, 175 miles. 
The Wind River mountains are clothed with excellent pine and other trees, but the imme- 
diate hills on either side of the Sweet Water are naked. Wood is found in the Black Hills 
and Park mountains, (of the amount I cannot speak positively,) and also in the Bear, Wah- 
satch, and Uinta mountains. 
Coal is found in quantity in various localities on branches of Green river; it is bituminous, 
and thought to belong to the odlitic period.* Captain Stansbury found seams of it ten feet in 
thickness, and he says the quantity is, apparently, unlimited. We have to regret, that after all 
the explorations in this belt of country, and after having so long been a highway to Oregon, 
Salt lake, and California, little is positively known about its geology. 
Of the great section of country lying east of the extended plateau of which we have been 
speaking, and which, beginning at the foot of the Black Hills at an elevation of about 5,000 
feet, reaches to the Mississippi, there is little to be said which is peculiar to the route under 
consideration. It has the same general features as in the other latitudes. In the eastern 
part it is a beautiful and fertile prairie, with wood upon the banks of the streams, and coal 
* See remarks of Professor James Hall, attached to Fremont’s report, 1842-’3—'4, p. 298. 
