INVESTIGATIONS IN THE COLUMBIA RIVER BASIN. 
175 
are many comparatively quiet nooks, however, in the broken, irregular walls, and the water is very 
deep, perhaps 20 to 50 feet. While these rapids are ipiite turbulent, trout and even other species of 
fishes have no trouble in ascending them. Trout (Salmo intjkiss) are common here, and in a large 
race which has been cut through the lava for milling xnirposes rve obtained m.any specimens of dace, 
chubs, and suckers {Catostonius ardcns). 
American Falls, Idaho. — At American Falls the Snake River is about 750 feet wide and flows but 
little below the general surface of the countiyy. The shores have no alirupt banks, the northern shore 
only being followed by a low, roundeil bluff 100 to 200 feet high. This was apparently composed of 
gravel, as no lava could be seen projecting from it. The outline of the American Falls is very irreg- 
ular. Its position is determined by a basaltic ledge crossing the river. The xiositiou of the edge of 
this ledge is now marked by a series of islands, between which the river flows and below which it 
falls. Tins same ledge can be traced for some distance along the edge of the canon below the fiills 
and is there seen to be underlaid by a layer of sandstone. At the falls, however, this seems not to be 
the case, the rock being lava from top to bottom. The western end of the falls is probably 200 to 300 
yards farther upstream than the eastern end. The front of the falls is located, therefore, very 
obliquely to the course of the stream. They show nowhere any great vertical height, 15 feet being 
probably near the maximum. In several places the falls are so broken down as to present only a 
short stretch of steep rapids, with gentler rapids above and below. Below the falls the water becomes 
immediately deep, but the rapids above are, at the stage of water seen, extremely shallow. On the 
eastern side of the stream, esxiecially, is a long stretch of these shallow rapids, in which the water 
averages not more than 6 inches deep, and it is here that the greatest obstacles to the ascent of fish 
would be found. When water is high in the spring, trout are seen to pass over the falls in large 
numbers, and it is probably true that even at a lower stage of water, as in the fall, fish can succeed 
in iiassing this obstacle. A fishway could be made here at very little expense were it considered 
desiral.)le. 
The stream here, as elsewhere in Idaho, flows through a country covered with sagebrush and the 
usual desert vegetation, bordered more or less thickly with willows. In the rapids at American Falls 
the rocks are thickly covered with green filamentous algm, and among the rocks are found very 
numerously crawfish, caddis worms, and other suitable food for fish. At American Falls the river 
descends about 70 feet and enters a canon, the surface of the country remaining about the same level, 
and from this point to below Sho.shoue Falls tlio stream descends deeper ami deeper into its canon by 
a succession of falls and rapids. It flows here through what is known as the “ Lava Beds ” of the 
Snake River, and the walls of its canon are composed of successive lava flows. But few streams find 
their way into the Snake River from the mountains of the north. As will be seen from the mail, the 
greater number of these on flowing down from the mountains sink into the lava and are lost. Of this 
kind are Birch Creek, Little Lost River, and Big Lost River. There is thus a great stretch of country 
bordering the river on the north entirely without surface water. Towards the west the Malacle or 
Wood River is the first stream to find its way into the Snake from the north. The water wliich thus 
sinks near the liaso of the mountains apparently reappears inside the canon of the Snake, coming out 
as great springs at the base of the cliffs. The best-known of these lie between the Shoshone Falls 
and Glen’s Ferry. They emerge from the loot of the cliffs often as large streams and are used to 
irrigate the l)ottom lands which Ijorder the river on the north at that point. 
The water of these streams is beautifully clear and cold; trout abound in them, and the smaller 
minnows run up from the Snake into them. Crawfish (.Istaciis gamhelii) also are very abundant. 
The temperature of the streams averages about 60'^, and they would be admirably adapted for 
hatchery purposes. The salmon visit this ])art of the river in sufficient numbers to furnish roe 
for hatching, and this is probably the most available point where suitable water and an abundance of 
fish can be found for such a station in Idaho. 
Unnamed Falls. — The next falls in the course of the stream were not visited by any member of 
the party, as nothing was heard of them until we had passed that region. Thej^ seemed to be unnamed. 
According to Mr. J. L. Fuller, of Bliss, Idaho, the river has a vertical fall of about 40 feet a short 
distance above the mouth of Dry Creek, the latter a small stream coming in from the south, nearly 
midway between American and Shoshone Falls. Mr. Fuller worked a mining claim at the mouth of 
Dry Creek at one time, and is therefore well acquainted with the falls, which he states to be vertical 
and impassaV)le to any kind of fish. 
Shoshone and Twin Falls. — The great obstacles to the passage of salmon up the Snake are found 
in Shoshone and Twin Falls, both of which are vertical and of great height. The erection of fish- 
