CHAPTER YII. 
General Geographical Description of the Rocky Mountains Region. 
Entering the mountains on the eastern side are the tributaries of Marias, Teton, Sun, Dearborn, 
and Jefferson rivers; the latter, one of the principal forks of the Missouri river. On the west the 
rivers Clark’s Fork of the Columbia, Blackfoot and Hell Gate forks, together with that branch of 
Bitter Root river retaining its name, and the tributaries of the Snake river, are the principal 
streams, whose valleys cut the mountains in transverse ranges, and whose sources are separated 
from the headwaters of the Missouri tributaries by ridges one to three miles in width, and rising 
from five hundred to two thousand feet above the running water on the opposite sides of the 
summit. 
Excepting the rocky and rugged peaks and ridges of unusual elevation, the mountain slopes are 
covered with wood, consisting of the different varieties of pine, (generally a species of yellow 
pine,) firs and spruces, a small proportion of white cedars, and occasionally an intermingling of 
the white birch. In the bottoms of the streams is found the bitter cotton-wood. The pines, and 
especially the pines of the valleys, will afford much superior lumber, and, as found in the bottom¬ 
lands of streams, and in the lower and easier mountain slopes, are tall and straight, and have 
a diameter of about three feet, and a height of from one hundred to one hundred and forty feet. 
The streams intruding into these wooded regions have in them a considerable amount of open 
and grassed lands. The valleys of the smaller tributaries of Clark’s fork are generally wooded 
until within a short distance of Flathead lake; both the Big and Little Blackfoot Fork valleys are 
wooded, but their bottoms contain m;my extensive and handsome prairies. Hell Gate fork has a 
growth of heavy pine and fir on the bordering hills, and an extensive prairie valley of eight hun¬ 
dred to one thousand square miles. St. Mary’s river has a handsome, open valley, six or eight 
miles wide, of even greater extent, and, in connexion with all the streams, is sufficiently supplied 
with pine and cotton-wood for the purpose of settlement. That portion of the Snake River 
valley explored was found to be destitute of timber, excepting in some places where the supply 
was good. The valley is generally very scanty in vegetation, almost the only growth being the 
wild sage. The valley for hundreds of miles is covered with beds of volcanic rock. Clark’s 
fork has an open, wide valley, extending to the Flathead lake, and in the vicinity of the temporary 
British trading post, about twenty miles south of the lake, is connected with several other smooth 
and fertile valleys, extending southeasterly into the mountains. All of these bottom-lands have 
a fertile, allhough sometimes a gravelly or stony soil, and touch upon forests abundantly supplied 
with valuable pine lumber. At the head and foot of the Flathead lake are open prairies, with 
good soil, and possessing the resources for a delightful farming location. The east and west sides 
of this beautiful lake are hilly and wooded; the eastern side thinly timbered. 
All these open lands are covered with an abundance of grass, and afford excellent pasturage for 
horses and cattle throughout the year. 
Between the headwaters of the Bitter Root and the Snake river the mountains are formed into 
low ridges, between which intervene valleys rich in grass and watered by mountain streams, and 
affording fairest grazing lands for the Indians with their large bands of horses. 
The country is abundantly watered with clear mountain streams, with pebbly beds; and lake 
and stream abound with fish. 
