THE YELLOWSTONE TROUT. 



{Salmo my kiss leivisi. ) 



In their valuable work ''The Fishes of 

 North and Middle America/' Doctors 

 Jordan and Evermann tell us that the 

 Yellowstone Trout may be found in "The 

 Snake River Basin above the Shoshone 

 Falls, and crossing the main divide of 

 the Rocky Mountains at Two-Ocean Pass 

 to the head waters of the Yellowstone, 

 thence to other affluents of the Upper 

 Missouri." In many localities within its 

 range this fish is quite abundant. It is 

 a variety of a species which is a native 

 of the clear and cold streams of Alaska 

 and Kamchatka. In those regions it 

 bears the vernacular name Mykiss. The 

 varietal name leimsi was given the Yel- 

 lowstone form in honor of Captain Meri- 

 wether Lewis, who in 1803- 1806 was 

 the leader of the memorable exploring 

 expedition of Lewis and Clark, and who 

 brought back specimens of this interest- 

 ing and g'amey fish. 



The typical form of the species mykiss 

 is represented by ten or more varieties, 

 each of which is the type found in the 

 waters of a circumscribed locality. The 

 Trout of our illustration is characterized 

 by a red marking on the throat which 

 has given the fish the name Cut-throat 

 Trout. This red mark is also present 

 on the throats of some of the other 

 varieties of the species. 



The Yellowstone Tro'Ut is of interest 

 for other reasons than those that would 

 naturally be advanced by the angler. 

 This fish is found on both sides of that 

 stupendous watershed, the Rocky Moun- 

 tains, on one side of which the streams 

 flow toward the Pacific Ocean, and on 

 the other toward the Mississippi River. 

 The Snake River of the west side and 

 the Yellowstone River of the east side 

 are connected by two streams which 

 cross the divide through Two-Ocean 

 Pass. It has been conclusively shown 

 by Doctors Jordan and Evermann that 

 the "Trout of the Yellowstone and the 

 Upper Missouri is derived directly from 

 that of the Upper Snake River." 



The physiography of the Two-Ocean 

 Pass region is so instructive, and its bear- 

 ing on the geographical distribution of 

 fishes is so important, that we quote the 

 description of Dr. Evermann regarding 

 the locality. 



He says : "Two-Ocean Pass is a high 

 mountain meadow, about 8,200 feet above 

 the sea and situated just south of the 

 Yellowstone National Park. It is sur- 

 rounded on all sides by rather high 

 mountains except where the narrow val- 

 leys of Atlantic and Pacific Creeks open 

 out from it. Running back among the 

 mountains to the northward are two small 

 canyons down which come two small 

 streams. On the opposite side is another 

 canyon down which comes another small 

 stream. The extreme length of the 

 meadow from east to west is about a 

 mile, while the width from north to south 

 is not much less. The larger of the 

 streams coming in from the north is 

 Pacific Creek, which, after winding along 

 the western side of the meadow, turns 

 abruptly westward, leaping through a 

 narrow gorge. Receiving numerous 

 affluents. Pacific Creek soon becomes a 

 good-sized stream which finally unites 

 with Buffalo Creek a few miles above 

 where the latter stream flows into Snake 

 River. 



'^Atlantic Creek was found to have 

 two forks entering the pass. At the north 

 end of the meadow is a small canyon 

 down which flows the North Fork. This 

 stream hugs the border of the flat very 

 closely. The South Fork comes down 

 the canyon on the south side, skirting the 

 brow of the hill a little less closely than 

 does the North Fork. The two, coming 

 together near the middle of the eastern 

 border of the meadow, form Atlantic 

 Creek, which, after a course of a few 

 miles, flows into the Upper Yellowstone. 

 But the remarkable phenomena exhibited 

 here remain to be described. 



"Each fork of Atlantic Creek, just 

 after entering the meadow, divides as if 



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