84 NAVIGABILITY OF THE MISSOURI. 
river, and at the several points for two miles above these rapids, at the ferry near the mouth of 
Swan river, and at the Little Falls. 
No difficulty will be experienced in locating the road from the plateau of the Bois des Sioux 
to the valley of Mouse river. It should keep south of the Shayenne, the northern limit of the 
plateau, to avoid the severe crossing of that river, and, pursuing a course north of the Dead Colt 
Hillock, keep along the dividing ridge between the Shayenne river and the Riviére a Jacques. 
On this portion of the road there is a scarcity of timber, and for a portion of the way water 
must be brought in aqueducts from the lakes on the Coteau du Missouri, which may be used both 
in running the road and in the growth of cotton-wood on the line of the road for supplies of fuel. 
Timber and fuel can be brought to the plateau in great quantities from the Red river of the North, 
and considerable supplies can be procured from the Shayenne. Lignite coal has been found on 
the Mouse river, and further search may lead to the discovery of beds of bituminous coal. 
3. From the valley of Mouse river the route to the plateau between the Milk and Missouri 
rivers must pass over the Coteau du Missouri at grades of not exceeding forty feet to the 
mile, and, descending into the valley of the Missouri river either by the Grand Coulée or the Big 
Muddy river, at grades not exceeding forty feet to the mile, can take two directions, either along 
the valley of the Milk river, toa point north of the Bear’s Paw mountains, or, crossing the Milk 
river near its mouth, can pursue an intermediate course between the Milk and Missouri rivers, 
passing through the Bear’s Paw mountains. 
The second route, involving the intricacies of the Bear’s Paw mountains, and not having been 
examined by an estimating engineer, will not be considered in this report. It will save perhaps 
twenty miles in distance, and should be examined previous to the location of the road. 
The valley of the Milk river has extraordinary railroad facilities—in its water, its groves of 
cotton-wood, its materials for ballasting; and is in connexion at several points with the Missouri 
river, as a line of supplies and communication to Fort Union, which may be reached by a spur 
road at the mouth of the Big Muddy, and at the mouth of the Milk river. This will render 
available for the road the resources in timber and stone of tle upper Missouri and Yellowstone. 
From the great lakes, therefore, to the plateau at the vase of the mountains, the road has 
several solutions, involving no higher grade than forty feet, and that for a few miles passing 
for the most part through a rich country, part of it heavily timbered and well watered; a deficiency 
of wood and water in other parts easily supplied by aqueducts, by the growth of cotton-wood, 
by the connexion of the Missouri and the Yellowstone, of the Red river of the North, the Shay- 
enne and the Mouse rivers. In this connexion I willrefer to the general character of the Missouri 
as a line of communication in the construction of the road. 
The Missouri is navigable as high as the mouth of the High Wood creek, fifteen miles below 
the Great Falls of the Missouri, by steamers drawing eightcen to twenty inches of water at all 
seasons of the year, when not obstructed by ice, and for steamers drawing two and a half to 
three feet for one-half the season. Its principal tributary, the Yellowstone, is also navigable for 
steamers for two hundred miles, and still farther for keel-boats and canoes. None of the rivers 
of the upper Missouri are navigable, except, perbaps, the Marias, which is said to be navigable 
for steamers of light draught some fifty miles. There are two rises in the river, occurring in May 
and June, caused by the melting of the snows of the prairies and the mountains, which facilitate 
very much the navigation of the river. The distance from its mouth to Fort Union is 1,900 miles, 
and to the mouth of the High Wood creek about 2,430 miles. From the mouth of the river to the 
Great Bend the country admits of almost continuous settlement; thence to Fort Union, only about 
one-fourth could well be cultivated. Above Fort Union there are many extensive bottoms 
adapted to agriculture, and much arable land in the vicinity of Fort Benton, especially on the 
High Wood creck. The immense quantity of game along the whole course of the river to below 
the Great Bend, is an evidence of its goodness as a grazing country. ‘The obstructions consist 
in snags, sawyers, and saud-bars, rapids, chains of rock, through which there is but one channel, 
