THE NORTHERN PACIFIC ROUTE. 141 
7,000 feet above the low, flat plains at its base make a topographic 
contrast that is rarely equaled in any other part of the Rockies. 
This remarkably abrupt front is due to the mountain range being a 
single huge block of the earth’s crust raised and tilted to the east and 
broken away from the block underlying the lowlands of the Flathead 
Valley, the unusually straight front of the mountains corresponding 
closely with the plane along which this break took place. 
The hills on both sides of the railway are made up of rocks of the Belt 
series, which show little variety in the different beds of which it is com- 
posed or in the positions in which they lie. The valley walls are gen- 
erally dark, and they are fringed on one side or the other by remnants 
of the lake terrace, which can always be identified by their light color. 
In the lower part of the valley, between Dixon and Paradise, the 
railway follows the banks of the river for several miles, and the 
traveler can obtain many attractive views of the broad river and its 
wooded islands, set off by the dark background of the rugged hills. 
Near Perma the river turns to the left and cuts a narrow canyon 
through the ridge which above this place bounds the valley on the 
left. In this part of its course the Belt series is cut by many dikes 
and sheets of igneous rock (diorite), showing that at one time there 
was considerable disturbance in the region. The most prominent of 
these igneous sheets shows in a bold hill on the north side of the river, 
nearly opposite milepost 50. The igneous material was intruded be- 
tween the layers of the sedimentary rocks, which subsequently have 
been turned on edge, and the diorite now forms a conspicuous out- 
crop for a number of miles to the north. 
At Perma another sill of the same sort as that described above 
crosses the river almost at the station, making a loop through the 
cliffs immediately to the left and then crossing the 
ule river about 14 miles farther west. This loop is 
“ekorepenge a caused by the folding of the sheet of igneous rock, 
together with the inclosing sedimentary beds, into a 
great anticline, but the -bedding is so obscure that the fold can not 
be traced from the train. : 
Twenty miles to the north is Camas Hot Springs, a small settle- 
ment where bath houses and hotels are maintained for the use of 
summer visitors who wish to bathe in the warm mineral water. 
Below Perma the canyon is deep and narrow, and its walls are very 
precipitous. Just beyond milepost 55 the railway crosses to the 
north side of Flathead River, at a point where several diorite sills 
has high, rocky walls that rise 1,500 to 2,500 feet above the valley 
floor. The rocks are dark brownish red, but 
broken rock below the cliffs are a much brighter red and give to the 
valley the appearance of being decorated with great red —— 
that are caught up at the base of the cliffs and stream down to the 
