FISH-CULTURAL INVESTIGATIONS IN MONTANA AND WYOMING. 
29 
MISSOURI RIVER BASIN. 
Atlantic Greek. — On August 18 we followed Atlantic Creek down to where, it flows 
into the Upper Yellowstone River. We seined it about a mile above its mouth and 
found a few young trout. At this point the creek is about 36 feet wide, f foot 
deep, and has a 3-foot, current. The temperature of the water at noon was 57°. Less 
than 2 miles below the pass the trail crosses Jay Creek, a few rods above where it 
joins Atlantic Creek. At the ford, Jay Creek was 20 feet wide, 8 inches deep, and had 
a current of 2J feet per second. The water at 10 :30 a. m. was 47°. About 2 miles 
further down, we crossed Senecio Creek about one-fourtli of a mile above its mouth. 
This is a stream much like Jay Creek, but considerably smaller. 
The Upper Yellowstone River. — We came upon the Upper Yellowstone at a point 
about 20 miles in a direct line above the lake, or 2 miles above Bridger Lake. Crossing 
it at this point, we traveled down the right bank to its mouth. This river is of good 
size and flows through a broad valley of meadow land which, in many places, has 
marshes bordering the river. 
According to Mr. Arnold Hague, the Upper Yellowstone River “rises in an 
immense snow field on the north side of an isolated peak, about 25 miles south of the 
southern boundary of the Park. The peak attains an elevation of over 12,250 feet 
above sea level, and has been long recognized as a prominent point by all topographical 
survey parties. Although never visited, it has been designated as Yount Peak, after a 
trapper who lived for a long time along the banks of the Yellotvstone. Three rivers — 
the Yellowstone, Gray Bull, and Buffalo Pork of Snake River — find their sources upon 
the abrupt slopes of this peak. To the southward and not far distant rises the Wind 
River. The region is an uncommonly rough one, with profound gorges penetrating far 
into the mountains and separated from each other by mere knife-edges of rock. The 
entire country is made up of volcanic material, for the most part andesitic breccia.” * 
We saw a great many young trout where we forded the river, and again near the 
mouth, where large fish were also abundant. A little time devoted to fly fishing here 
resulted in the capture of six very fine trout, 14 to 18 inches long, every one of which, 
however, was infested with the parasitic worm JDibothrium cordiceps. The temperature 
of the river near its mouth at 3:30 p. m. was 57°; air, 68°. Throughout most of its 
course the Upper Yellowstone River has a clean, gravelly bottom and flows with a 
good, strong current. 
Bridger Lake lies just outside the original Park boundary and between the 
Yellowstone River and Thoroughfare Creek. This is a pretty little lake, about a mile 
long by half a mile wide, and is well filled with trout. 
Thoroughfare Greek. — This is the largest tributary of the Upper Yellowstone 
River. At our camp, just at the Park line, it is fully 100 feet wide, 2 feet deep, and 
flows 3 feet per second. Temperature of water at 5 p. m., August 18, 60°; at 7 :30 a. in., 
the next day, 45°; temperature of air at 6:30 a. m., 31°. We seined this stream very 
thoroughly, but found nothing except numerous very young trout. A good deal of fly 
fishing did not result in a single catch. The water is clear and pure and full of fish 
food of various kinds. 
Hague, in Powell’s Ninth Annual Report, page 93. 
