Vegetation is abundant in the lake as well as around it. Several species of plants grow far out into the deep waters, living thickly on rocks twenty feet below the surface. After a severe storm their uptorn stems strew the beach like kelp on the seashore, and the water is discolored with vegetable matter for several yards from the shore. The water swarms with trout, but there is no other kind of fish, no shells, no shell-fish,—nothing but trout. Of these, Mr. Carrington, the naturalist of the Geological Survey, reports the following interesting observations:
"Although I searched with diligence and care in the neighboring streams and waters around the Yellowstone Lake, I was unable to find any other species of fish except the salmon-trout; their numbers are almost inconceivable; average weight, one pound and a half; color, a light-grey above, passing into a light-yellow below; the fins, all except the dorsal and caudal, vary from a bright-yellow to a brilliant orange, they being a dark-grey and heavily spotted. A curious fact, and one well worthy of the closest attention of an aspiring icthyologist, is connected with these fish, namely, that among their intestines, and even interlaced in their solid flesh, are found intestinal worms, varying in size, length, and thickness, the largest measuring about six inches in length. On cutting one of these trout open, the first thing that attracts your attention is small oleaginous-looking spots clinging to the intestines, which, on being pressed between the fingers, break and change into one of these worms, small, it is true, but nevertheless perfect in its formation. From five or six up to forty or fifty will be found in a trout, varying, as I said before, in size, the larger ones being found in the solid flesh, through which they work their way, and which, in a very short while, becomes almost putrid. Their number can generally be estimated from the appearance of the fish itself; if many, the trout is extremely poor in flesh, the color changes from the healthy grey to a dull pale, it swims lazily near the top of the water, losing all its shyness and fear of man; it becomes almost savage in its appetite, biting voraciously at anything thrown in the water, and its flesh becomes soft and yielding. If, on the other hand, there are few or none, the flesh of the fish is plump and solid, and he is quick and sprightly in all his motions. I noticed that it was almost invariably the case when a trout had several scars on the outside of his body that it was free from these worms, and I therefore took it for granted that the worms finally worked their way through the body, and the flesh, on healing up, leaves the scars on the outside; the trout, in a short while, becomes plump and healthy again. The only way that I can account for the appearance of these worms is, that the fish swallows certain bugs or insects, and that the larvæ formed from them gradually develop into the full-grown intestinal worm. But even if this explanation of their appearance was received, does it not seem a little strange that while all the fish above the Upper Falls are more or less affected by them, that below and even between the Upper and Lower Falls such a thing as wormy trout is never heard of? Being unable, with my limited knowledge of icthyology, to arrive at any definite conclusion in regard to their appearance, I submit the above facts to those who are more learned than myself in this most interesting branch of natural history."
Waterfowl make up in number and variety for the lack of life within the lake. The surface fairly swarms with them. Lieutenant Doane enumerates swans, pelicans, gulls, geese, brants, and many varieties of ducks and dippers; also herons and sand-hill cranes. The pelicans are very plentiful, immense fleets of them sailing in company with the majestic swan, and at nightfall the low, flat islands in the lake are white with them. The gulls are of the same variety as those of San Francisco Harbor. Eagles, hawks, ravens, ospreys, prairie chickens, grouse, mocking-birds and woodpeckers are common in and around the lake basin. Mention is also made of a guide-bird, whose habits correspond with its name. It resembles the blackbird, but is larger. Lieutenant Doane says:
"I saw but one of these—the day I went to the bottom of the Grand Cañon; it hopped and flew along from rock to rock ahead of us during the whole trip down, waited perched upon a rock while we were resting, and led us clear to the summit again in the same manner, making innumerable sounds and gestures constantly to attract attention. Others of the party remarked birds of the same kind and acting in the same manner."
Herds of deer, elk, and mountain sheep, throng the forests and mountain meadows about the lake. Buffalo signs, grizzly bears and California lions are far from uncommon, while the smaller lakes and creek-valleys of the basin are fairly alive with otter, beaver, mink, and muskrats. Lieutenant Doane observed several unnamed and undescribed species of squirrels and weasels, and doubtless there are many other new varieties of animal life peculiar to this little-known region. One department of natural history, however, is happily unrepresented in the basin. There are no snakes, though rattlesnakes are plentiful down the Yellowstone.
There are but two considerable islands in the lake—Stephenson's and Frank's—each about a mile long, narrow and covered with a thick growth of pines. Dot Island, near Frank's, a small lozenge-shaped mud-bank, not over a third of a mile long, and half a dozen of smaller size, usually near the shore, complete the list.
The first explorers constructed a rude raft for the purpose of visiting these islands and exploring the shore-line of the lake, but it was speedily wrecked by the choppy waves beat up by the sudden gusts from the mountains. The Geological Expedition took the precaution to carry from Fort Ellis the framework of a little craft, twelve feet long, three and a half feet wide, and twenty-two inches deep, which, covered with well-tarred canvas, made a very serviceable boat for fair-weather navigation. "Our little bark, whose keel was the first to plow the waters of the most beautiful lake on the continent," says Dr. Hayden, "was named by Mr. Stephenson in compliment to Miss Anna L. Dawes, the amiable daughter of Hon. H. L. Dawes. My whole party," he adds, "were glad to manifest, by this slight tribute, their gratitude to the distinguished statesman, whose generous sympathy and aid had contributed so much toward securing the appropriation which enabled them to explore this marvellous region."
THE FIRST BOAT ON YELLOWSTONE LAKE.