54 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
the whitefish might have done so also; but this is unlikely, as no whiteflsh are now in 
Yellawstone Lake nor in Yellowstone Eiver above the falls. The Yellowstone is a 
very clear, cold stream (temperature 50° to 60°), and, taking its whole extent, it is 
one of the most picturesque in America. It flows through a large glacial depression 
in which it expands to form the Yellowstone Lake (7,741 feet elevation). This is a 
large body of water, of very irregulai' form, which is often compared to that of an 
uncouth hand with a very large thumb and three shrunken fingers. Its greatest 
length, north and south, is about 22 miles, and its greatest width across the thumb is 
about 15. West and south'of the lake are high mountains, and the lake banks are, in 
many places, bold and rocky, the hills being covered with pine and fir trees. Toward 
the north end of the lake the banks are lower, ami here terraces show previous greater 
extension, covering the marshy pastures and woodlands of its outlet, the territory 
known as Hayden Valley. 
Above the lake the Yellowstone Eiver winds through marshy meadows, between 
wooded hills, behind which are the rugged peaks of high volcanic mountains. The 
current is sluggish above the lake, and between the lake and the upper falls there is 
also no great descent. The river below the lake is bordered by low hills, some of them 
wooded, others forming open grassy pastures. Below the lake the large river flows 
for about 15 miles with a quiet current, then plunges into a deep canon over two ver- 
tical falls 109 feet and 308 feet in height (see iflates XI, XII, XIII). This famous 
canon, which needs no description here, is more than 20 miles long, with nearly per- 
pendicular walls, 800 to 1,100 feet in height. The current of the stream below the 
falls is swift until it leaves the Park. The Yellowstone retains its general character 
as a clear, cold, and swift river for almost its whole course through Montana until it 
joins the Missouri. Trout abound throughout from the source of the river in the 
mountains as far as Livingston, and doubtless for many miles beyond. Above the 
falls the river contains no other kind of fish. The abundance of trout above the falls 
is remarkable. In one eddy in the river, eleven, averaging 3^ pounds each, were seen 
together, and in parts of the lake they are as numerous as in the river. They are 
everywhere eager to take the fly, but they are regarded as indifterent fighters in com- 
parison with the trout of other streams. 
In Yellowstone Eiver, and in most parts of the lake, fish-food, such as insects, 
Crustacea, larvm, etc., are very abundant. The stomach of one trout taken in the river 
contained helgramites (larvae of Corydalus), grasshoppers, and caddis-worms. 
Of the tributaries tf the Upper Yellowstone, none were visited by us. Common 
report says that all are well stocked with trout, and that the trout in all or most of 
them are wormy. 
The following tributaries of the lake were examined : 
Solution Creelc is a small, narrow^ stream, with lava bottom and grassy banks lined 
with willows. At the time of our visit it was dry for 2 or 3 miles above its mouth, and 
for about the same distance below its source in Eiddle Lake. In the standing pools 
of its middle course were numerous young trout. 
Biddle Lalce (so called because of the mystery of its outlet, “ solved ” by the dis- 
covery of the little creek) is a clear pond of roundish outline about 1^- miles in diame- 
ter. About its outlet are numerous lily-pads and other plants. Its shores are shal- 
low, and its bottom chiefly lava gravel. Trout seem to be numerous in the pond. Two 
were taken, one a female with full ovaries, the other a male with shrunken testes. 
