GEOGRAPHICAL MEMOIR. 237 
hardy population will grow up. There will be no difficulty about supplying such a population 
with water, or with wood for buildings, for the Missouri itself from the Gate of the Mountains 
can carry down the timber required for a considerable population. From the Bears Paw to 
the Rocky mountains the great feature of the country is, first, the extension of the plateau to 
the base of the mountains, and the comparatively gentle and gradual approach which it 
furnishes; and, second, the extraordinary network of streams which, passing down from the 
main chain, form by their several junctions the southern tributary of the Saskatchawan, Milk 
river, Marias river, Teton river, Sun river, and Dearborn river. 
The numerous branches of the Milk, Marias, Teton, and Sun rivers all have beautiful and 
fertile valleys, while, even in the mountains, numerous rich prairies are met with, and the hills 
themselves are often covered with a fertile soil. The character of the country is even better for 
agricultural purposes close to the mountains than further off. In the vicinity of Birch and 
Badger rivers it was beautiful, and even in May covered with a luxuriant green turf and 
numerous flowers, the soil being a dark loam. The main stream of the Marias came from a gap 
in the mountains, ten or fifteen miles in width, the valley partially timbered and partially rich 
prairie. This stream, evidently not the one explored by Mr. Tinkham, seemed to lead through 
the true Marias Pass; going up the valley for several miles, he still found it wide, and without any 
apparent obstruction towards the west, while the stream continued so deep that һе found a ford 
with difficulty. 
The valleys of the numerous streams he crossed, between Sun river and the upper streams of 
Milk river, occur so close together that there can be no deficiency of water; not only the valleys 
but a great part of the upland is arable. Sun river, with its south fork, called Elk Fork, eight 
streams running into the Teton, seventeen tributary to Marias, and ten sources of Milk river 
were crossed in this intervale of 140 miles, having each an intervale of from a half a mile to 
ten miles in width, with an abundance of excellent timber in close proximity. 
Coursing along under the eastern base of the mountains, in the months of May and June, you 
constantly cross these little streams, having a volume of water, showing that they have a 
considerable course over a country much of it arable, and all decked out in the gayest flowers 
of spring. The Mo-ka-un, or Belly river, a tributary of the Saskatchawan, has its rise in Chief 
Mountain lake, under the 49th parallel, which is fed by several tributaries, whose most southern 
source is about latitude 48° 20. About the Chief Mountain lake, in the neighborhood of these 
several tributaries and to the eastward, is much arable land. 
Standing on one of the elevated mountain peaks near this Jake, and looking to the northeast 
upon the country through which passes this tributary of the Saskatchawan, a vast plain, or more 
properly a prairie, is spread before the eye for more than fifty miles, for in richness of soil, luxuriant 
vegetation, and bright colored flowers, it closely resembles the prairies of the western States. 
The river next in size to the Milk, on the northwest side of the Missouri, is the Marias, which, 
rising in the Rocky mountains about latitude 48° 30’, runs a little south of east for about one 
hundred and sixty miles in a direct line, though much more by its windings, and empties into the 
Missouri eleven miles below Fort Benton. It is supposed to be navigable for small steamboats 
for fifty miles, forming the extreme of water communication towards the northwest in longitude 
1119 30. About a mile above its mouth it receives the Breast or Teton river, which, flowing 
from the mountains near latitude 48°, has a more winding but general easterly course for about 
one hundred and thirty miles, and is a smaller stream than the Marias. The next met with is 
Medicine or Sun river, which, rising also in the main range about latitude 47° 30', pursues а 
