1 877,] Prof. Hayden s Explorations 4 > 249 
The Yampah, or Bear River, deviates from a westerly 
course only for a few miles occasionally. Like White River 
it flows through a plateau country, which rises gently from 
the river, back for a distance of about eight miles. South of 
the river lie the Williams River Mountains, which have a 
gradual slope to the north. Williams fork, flowing from a 
south-eastern direction, joins the Yampah river west of the 
junction. The Yampah traverses the country more or less 
in a canon, occasionally emerginginto an open grassy valley, 
then enters a deep canon, cuts through the Yampah Moun- 
tains, when it joins with the Snake River. The place of 
junction resembles a fine park, surrounded on all sides with 
eroded terraces and plateau spurs that rise by steps to the 
divide on either side. This park is about 8 miles in length 
from east to west. After leaving this park the river enters 
a hugh fissure in the mountains, where it remains, until, 
completing its zigzag course, it joins the Green River in 
longitude iog°4o', and latitude 32°. After the junction with 
the Yampah, the Green River continues in a canon for 
14 miles, where it passes through the picturesque palisades 
of Split Mountain into an open broad valley, longitude 
109° 15', latitude 40° 28', from which point it takes a south" 
west direction through the Wamsitta Valley, where it unites 
with the White River. Into both White and Yampah 
Rivers numerous branches extend from either side, forming 
deep canons the greater portion of their length. We may 
say, in brief, that the sides of the valleys expand and con- 
tract, at one time forming the beautiful grassy valleys which 
in olden times were celebrated as the favourite wintering 
places for the trappers, or contracting so as to form narrow 
canons or gorges with walls of varied height. 
The walls of Yampah canon average about 1000 feet, 
while the mountains, receding back to the northward, attain 
an elevation of 4200 feet, while the highest point of the 
plateau on the south side is 3400 feet above the river-level, j 
Of the plateaus between White and Yampah Rivers, Yam- 
pah plateau is the largest, and occupies an area of 400 square 
miles. The surface of the summit is undulating, and on the 
south side it presents a steep face, several hundred feet in 
height, covered with debris , rendering it almost inaccessible. 
This plateau is covered with excellent grass, and gives origin 
to numerous springs, all of which dry up within a short dis- 
tance of their source. 
As a whole, this district is very arid, barren, and almost 
destitute of tree vegetation. 
The total number of stations made by Mr. Bechler in the 
