THE NORTHERN PACIFIC ROUTE. 159 
Between mileposts 77 and 78, west of Irvin, the railway crosses 
Spokane River, the water of which is so beautifully clear that every 
object on the bottom is plainly visible. Near this point the military 
road constructed by Lieut. Mullan crossed Spokane River. This 
road entered the main valley from the southwest, east of the present 
city of Spokane, and then extended up the valley to Coeur d’Alene 
Lake. 
West of the railway bridge the surface of the country to the south 
is littered with large bowlders composed of many kinds of hard rock, 
which the ice brought down from the north. From their abundance 
it is supposed that these bowlders mark the point of greatest advance 
of the ice and are in the nature of a terminal moraine, although no 
distinct ridge or other characteristic topographic feature has been 
left in the valley, as is usual at the extremity of a glacier. 
Although the basalt covers most of the country in this vicinity, 
it did not engulf all the hills, for the highest knob on the north, Little 
Baldy, composed of schist, stood above the molten flood that rolled 
into this region from the west. The low hills on the left are com- 
posed wholly of basalt, which also shows near the river in the out- 
skirts of the city of Spokane. Here it can be seen at close range as 
the train passes through the deep cuts on its way to the station." 
1 Spokane River has been beset by | time the stream was obstructed and its 
many difficulties in carving its present | valley greatly modified, but with the 
channel. At the time the great flood of | disappearance of the ice it again set to 
lava inundated the region, there was | work to carve a valley suitable for a 
evidently a deep valley here which was | stream of its size. Work was begun near 
flooded with the molten material. This | its mouth, but gradually its gorge has 
inundation did not come as one great | been extended upstream until the fall, 
wave, but doubtless flood succeeded | which marks the point where active 
flood with fairly long intervals between | cutting is in progress, has reached its 
until the lava was piled up to a great | present position in the city of Spokane. 
thickness, nearly obliterating the orig- | Here the river makes a series of plunges 
inal channels. over precipitous slopes of basalt. Orig- 
When the outpourings of lava ceased, | inally this formed a beautiful fall as the 
the water found an outlet in part along swirling waters broke against al a 
the old courses, but in most localities the | rocks in their d i plunges, but now 
eruptions changed the face of the entire the stream has been obstructed for the 
country, so that the streams were com- | third time by a dam, and the water has 
pelled to carve for themselves new valleys | been diverted by man for the production 
in the hardened lava. This process was | of power. The beauty of the falls is gone 
well along when the great glacier, laden 
with the rocky fragments it had plucked 4 
from the valley walls, swept down the ' D 
valley. The materials carried by the 
glacier were distributed by the streams 
flowing from the ice front and scattered | J 
over the entire valley, filling it to the | ing mines and 
height seen to-day. Thus for the second ! district. 
