FISHES OF THE YELLOWSTONE NATIONAL PARK. 7 
quisite coloration. The adult averages about 1 pound, but may 
attain a weight of 4 pounds. 
The grayling prefers swift, clear, pure streams, with gravelly or 
sandy bottom. Tt is quite gregarious, lying in schools in the deeper 
pools, in plain sight, and not, like the trout, concealed under pasties 
and overhanging banks. In search of food, which consists prin- 
cipally of insects and their larvie, it occasionally extends its range to 
streams strewn with bow!ders and broken rocks. 
Unlike the native trout, the grayling will go long distances, if 
necessary, to find suitable spawning grounds. It spawns in April 
and May on gravelly shallows. In the north fork of the Madison 
River, where the water is comparatively warm, coming from the 
Firehole River in the park, the grayling spawns a month earlier than 
in any other waters in Montana. 
In point of activity it even excels the native trout, when hooked 
breaking the water repeatedly in its effort to escape, which the trout 
seldom does. It takes the artificial fly eagerly, and if missed at the 
first cast will rise again and again from the depihs of the pool, whereas 
Fia. 1.—Montana grayling. 
the trout will seldom rise a second time without a rest. It will also 
take various baits, such as caddis-fly larve, grasshoppers, and worms. 
Among the recommended flies are professor, Lord Baltimore, queen 
of the water, grizzly king, Henshall, coachman, and various gauze- 
winged flies, with No. 10 and 12 hooks. As a food fish it is even 
better than the trout, its flesh being firm and flaky, very white, and 
of delicate flavor. The grayling is artificially propagated in Mon- 
tana by the United States Bureau of Fisheries and the State fish 
commission. 
2. Rocky Mountain Wuiterisu (Coregonus williamsoni). 
The Rocky Mountain whitefish occurs in all suitable waters on 
the west slope of the Rockies from Utah to British Columbia. A 
scarcely, if at all, distinguishable variety or subspecies bearing the 
name of Coregonus williamsoni cismontanus is fennel in certain waters 
of the upper Missouri Basin. In some localities this fish is miscalled 
grayling,* with which it should not be confused, as it is a very differ- 
ent species, and there seems to be a local Yellowstone River name, 
the phonetic spelling of which is “sterlet” or ‘‘steret.”’ 
4 Referring to the fishing in the canyon of Sunlight Creek, Clark Fork, Ralph E. Clark probably made 
this mistake in writing the following: ‘‘ You will probably first catch a scaly fish which looks like a long 
sucker. It is the Montana grayling, and there are many down there.” 
