44 ROUTE NEAR THE FORTY-SEVENTH AND FORTY-NINTH PARALLELS. 
Of the first, Governor Stevens says: ‘‘The route will be long, in consequence of the curves 
of the river, “and will involve curves of the minimum radius, numerous bridge-crossings, con- 
siderable side-cutting, and high embankments on the prairie portions, in consequence of the 
spring freshets (twenty to thirty feet vertical rise.) The rock, in side-cuttings, can be easily 
quarried. The greater portion of this route has been personally examined by me, and I am 
satisfied of its practicability, though at great expense.’’ 
Mr. Lander, in whose judgment and experience Governor Stevens placed great confidence, 
says of this portion of the route: ‘* The*descent of the Bitter Root is very severe. The general 
grade of the river-valley for that distance is not great (11,1, feet per mile,) but the changes 
in level are abrupt, the valley extremely narrow and crooked; sharp curvature and steep 
gradients will be needed under any system of location, and, by the best mode of conquering 
these difficulties, the line will be extreme in cost and nearly impracticable.’’ 
The only instrument used on this examination was a pocket-compass. Governor Stevens’s 
party left the Bitter Root at the debouche of the Coeur d’ Alene Pass, and Mr. Lander ata 
point several miles before reaching Clark’s fork. The topographer of the expedition, Mr. 
Lambert, describes this unexamined portion of the Bitter Root as a cation, but in conversation 
I find that his description was inferred from partial information, and was not intended to 
mean that the mountain-sides closing in upon the river were vertical walls. Dr. Suckley 
makes no special mention of it. In respect to this portion of the route, he says: ‘‘ The numer- 
ous very short curves, obliging frequent crossings by strong bridges, the great length of the 
route if the river is followed, the steep banks, and the high-raised work necessary to prevent 
the encroachinents of the freshets, (which in many places rise from twenty to thirty feet above 
the common level,) will all render this part of the road exceedingly expensive.’’ In view of 
the difficulties to be encountered on this line, and of the nature of the reconnaissance of it, it 
should not be considered practicable until more exact data are obtained upon which to form a 
correct opinion. 
By the second line to Clark’s fork: To overcome the summit of the Jocko divide, 852 feet 
above Hell-Gate, the approach will require a grade of sixty feet, and the descent to the valley 
of the Jocko a grade of sixty feet, both for short distances, with heavy embankments, and prob- 
ably a lofty bridge. Lieutenant Donelson is of opinion that these grades may be reduced to 
forty-five and forty feet. Along the valley of .the Jocko and Flathead rivers, on their left 
banks to Clark’s fork, the grade will be twenty feet per mile. Ten or twelve miles before 
reaching Clark’s fork, the mountains close in upon the river with steep slopes and rough pro- 
jecting rocks. The heavy growth of timber obliged the party to leave the river, returning to 
it again at Horse Plain on Clark’s fork, a few miles below the junction of the Bitter Root and 
Flathead. This portion of the Flathead, like that of the Bitter Root, is described by Mr. 
Lambert asacaton. The distance to Horse Plain from Hell-Gate by the Jocko is 70 miles, 
by the Bitter Root 95 miles. 
A better connection with the Flathead can probably be made by leaving the Blackfoot 
valley above the defile ; further examination is necessary to establish this, however. 
Lieutenant Donelson says the average fall of Clark’s fork is eleven feet per mile, and he 
estimates that the railroad could descend with gradients of from fifteen to twenty feet per 
mile. With the exception of occasional small prairies, marked on the map, ‘its valley 
throughout is heavily timbered, mainly with pine. At several points on the route the rocky 
hill-sides crowd upon the river, and all deep-cutting will probably expose the rock, appa- 
rently, in general, a species of limestone or trap. 
The line crosses the Flathead some miles above its junction with Clark’s fork, (or Bitter 
Root?) continues on the right bank as far as Big Rock; then crosses Clark’s fork, following 
the left bank, and recrosses at the Cabinet mountain. Tunnelling the Cabinet mountain 300 
yards through 50 per cent. basaltic rock, it would continue on the right bank of the river to 
