I- 



THE FISHES OF THE YELLOWSTONE PARK. 



BY DAVID S. JORDAN. 



^ Not long: ago the writer was directed by the U. S. Fish Commis- 

 sioner, Hon. Marshall McDonald, to make an examination of the 

 streams of the Yellowstone Park, with a view to finding- the dis- 

 tribution of the species of fishes there, and also to give direction to 

 the work of stocking the streams with trout and grayling. 



In September last, the writer, assisted by Dr. Charles H. Gilbert, 

 spent three weeks in such explorations. A k\v of the facts ascer- 

 tained are given in this paper. 



The Park region is an elevated plateau of lava, traversed by many 



clear mountain streams, and with a number of large lakes of glacial 

 origin. 



On all sides of the plateau, excepting the southeast, wherever the 

 streams leave the lava-plateau they have cut deep canons, and at 

 the head of each canon there is a waterfall. These falls vary in 

 height and steepness, the highest being the vertical fall of the Yel- 

 lowstone, but almost all of them constitute an impassable barrier to 

 the ascent of fishes. 



The original lava flow, which dates from Tertiary times was, of 

 course, fatal to all life in this region. If the fishes ever invaded the 

 region after the suface of the lava became cold, the snows of the 

 glacial period must have again driven them out. Since the glacial 

 period the formation of falls and canons have effectually prevented 

 their return, except in a few cases noted below. 



It has thus resulted that a territory of 1.500 square miles, nearly 

 half the area of the Park, is wholly destitute of fish. This com- 

 prises the drainage of the Gardiner, Gibbon, Fire-hole, Nez Perce, 

 Tower and Lewis rivers, with Shoshone and Lewis lakes. Among 

 these are some of the clearest and coldest streams of the Rocky 

 Mountains, streams in every way suitable for the maintenance of 

 trout. If the popular idea that each species of animal has been 

 placed in those regions most suitable for its development be cor- 

 rect, the failure to fill these streams with fish must be regarded as 

 a great oversight on the part of Mother Nature. Besides this fish- 

 less area within the Park, there is another perhaps equally large, 

 further east, on Clarke's Fork of the Yellowstone. In all these 

 streams they are placing trout and grayling, and it is the intention 



