134 GUIDEBOOK OF THE WESTERN UNITED STATES. 
miles west of Bonner, Hell Gate Canyon terminates abruptly,’ and a 
short distance beyond this termination is situated the flourishing town 
of Missoula 
From the station at Missoula a good view may be obtained of the 
steep side of the valley, which rises like a mountain on the east. The 
knob north of Hell Gate Canyon is Jumbo Mountain, 
and the larger mass south of the canyon is University 
Mountain. The slopes of these mountains are free 
from trees and brush, and on looking closely it will be 
seen that they are marked by many horizontal lines 
(fig. 29) which become very prominent when they are covered by a 
slight fall ofsnow. These 
lines have attracted gen- 
eral attention, and many 
theories regarding their 
origin have been sug- 
gested. Some have sup- 
posed that they are stock 
trails, but it is now gener- 
ally agreed that they are 
undoubtedly beach lines 
cut by a body of water that 
occupied the broad valley 
in which Missoula is situ- 
ated and also many other 
valleys in this part of the 
mountains. According to the markings on the valley walls, the water 
must have been nearly 1,000 feet deep where Missoula now stands.2 
Missoula, one of the most important towns of western Montana, is 
situated on a broad plain at the lower end of Bitterroot Valley, which 
extends southward for a distance of at least 75 miles. It is the junc- 
tion of a branch line of the railway which runs up the Bitterroot Valley 
to Stevensville, Hamilton, and Darby. At Missoula is located the 
University of Montana, and a little below the town, on the opposite 
' The east wall of the valley at Missoula 
is so abrupt and regular that it at once 
Missoula. 
Elevation 3,223 feet. 
Population 12,869. 
St. Paul 1,248 miles. 
FIGURE 29.—Horizontal beach lines on Mount Jumbo, as seen 
from railway station at Missoula, Mont. 
they are continuous along both sides of 
the valley, is the depression of the block 
suggests a fault—that is, the mountain has 
tain have been raised or those on the east 
depressed, forming the long, straight 
Bitterroot Valley. The effect of the 
movement on these. two fault planes, if 
of strata between them forming the floor. 
of the Bitterroot Valley, as illustrated in 
figure 23 (p. 112). As the hard rocks 
under the valley are poorly or not at all 
, the evidence of the fault at 
Missoula is to be found only in the topog- 
raph: 
oO 
y. 
* The horizontal beach lines that are s0 
well shown along the railway at Missoula, 
in the Jocko Valley, and at Plains, below 
Trout Creek, in the valley of Clark Fork, 
