14 U. S. BUREAU OF FISHERIES. 
beyond the park boundary. Named in order from the south to north 
they are Cougar, Gneiss, and Grayling Creeks. Within the park 
Cougar Creek receives the waters of Maple Creek, the principal tribu- 
tary of which is Duck Creek. These upper waters are inhabitated by 
native redthroat trout. Campanula Creek joins Gneiss Creek beyond 
the park boundary. It also contains redthroat trout, as do the 
upper waters of all three of the main creeks mentioned, and in their 
lower courses they have whitefish and grayling besides native trout. 
The main Madison appears to contain a mixture of all the trouts 
that occur in the park, as well as whitefish and grayling. 
SNAKE RIVER DRAINAGE. 
Above its junction with Heart River the Snake pursues a north- 
west course, receiving numerous small tributaries, the most important 
of which is, perhaps, a branch which heads in Mariposa Lake. Two 
relatively large tributaries come in from the northeastward—Crooked 
and Sickle Creeks. 
Mariposa Lake is a small body of water in the southeast corner of 
the park about a mile north of the park boundary. It is said to be 
alive with native redthroat trout and to afford wonderful fishing for 
large trout. About a mile beyond the boundary Bridger Lake is 
another remarkable native trout water. 
Heart Lake, about 34 miles long and not quite 2 miles in width, 
lies in a deep depression at the eastern foot of Mount Sheridan. 
Near the head of the lake and in the lake are numerous geysers and 
hot springs. Its bottom is of laval gravel, rather shallow near the 
shore but becoming deep in the middle. It receives some small tribu- 
taries, principal of which are Witch and Beaver Creeks. Heart River, 
its outlet, just below the lake receives a comparatively large tributary 
known as Surprise Creek. 
Witch Creek has its rise 2 or 3 miles above the lake, in the singular 
collection of geysers, hot springs, and steam holes known as Factory 
Mill. Its water is at first scalding hot, but it gradually cools, receiv- 
ing the waters of one cold tributary as large as itself. The lower 
course of Witch Creek winds through grassy meadows, with a bottom 
of fine laval gravel and sand. The creek at its mouth has a tempera- 
ture of about 75° F. Native redthroat trout are numerous, occurring 
most commonly about the mouth of the creek. Besides the trout 
are suckers, chubs, and shiners, and the blob, or fresh-water sculpin, 
also occurs. There is plenty of fish food in the lake. The tempera- 
ture varies according to the nearness to hot springs and geysers. 
Trout are said not to ascend Witch Creek, although the other species 
do, the chubs ascending until the water is fairly to be called hot. 
Beyond the mouth of Heart River the Snake bends to the south- 
ward, thence later to the westward, receiving a number of tributaries, 
the largest being Basin Creek, Red Creek, and Forest Creek from the 
north. All the tributaries flowing directly into the Snake contain 
native redthroat trout. 
Lewis River, which joins the Snake just within the park boundary, 
is the outlet for the waters of Shoshone and Lewis Lakes. 
