18 U. S. BUREAU OF FISHERIES. 



In the park it naturally occurs in the Yellowstone River below 

 the falls as far up as Crevice Gulch, beyond which it is seldom found, 

 in Madison and Gallatin Rivers below the falls, and has been reported 

 also from the junction of Firehole and Gibbon Rivers. At the 

 junction of Lewis and Snake Rivers "grayling," or " mountain 

 herring," are reported as taken by anglers; these are doubtless 

 whitefish. 



Young whitefish 2 to 5 inches long from Montana were planted in 

 park waters, as follows: In 1889, 2,000 were placed in Twin Lakes 

 and 980 in Yellowstone River above the falls, and 10,000 more were 

 planted in the latter place in 1890. It is considered doubtful if any 

 of these have survived, owing to the number and size of voracious 

 trout in the Yellowstone River and the mineral character and high 

 temperature of Twin Lakes. 



This fish prefers clear, cold lakes and streams, where the usual 

 length of adults is about a foot, although it is known to have attained 

 a weight of 4 pounds. The cismontanus form is essentially a river 

 fish rather than an inhabitant of lakes and is most abundant in the 



FIG. 2. Rocky Mountain whitefish. 



eddies or deeper pluces of swift streams. It spawns in late fall or 

 early winter. This is a slender, graceful fish, readily taking the arti- 

 ficial fly like a grayling or trout, as well as natural baits, such as 

 worms and insects and even fresh meat. However, owing to the 

 smallness of its mouth, the hook should be no larger than No. 10 or 

 12, and when hooked the fish requires careful " playing " owing to 

 the tenderness of the mouth parts. It is a game fighter. It ranks 

 high as a panfish, for, when in condition, it is of surpassing sweetness 

 and delicacy of flavor. 



3. REDTHROAT TROUT- CUTTHROAT TROUT; BLACKSPOTTED TROUT 



(Salmo lewisi). 



(See frontispiece.) 



In its numerous varietal, subspecific, or specific forms the red- 

 throat, cutthroat, or blackspotted trout is of extensive distribution 

 on the Pacific slope. In the park a form designated as Salmo lewisi 

 is found naturally in both upper Snake and upper Missouri waters, 

 having doubtless gained access to the latter from the Snake River 

 bv the way of Two Ocean Pass, and it is not unlikely that an inter- 

 change of individuals still takes place. 



