24 SNAKE RIVER PLAINS OF IDAHO. [bull. 199. 
FAUNA. 
On the plains, more especially in the broader portions in the vicin- 
ity of the three prominent buttes that break their monotony, big- 
game is still to be found. Antelope roam over them throughout the 
year, while deer and elk find there a safe winter range. The moun- 
tain sheep is also present in winter, and the mountain goat is reported 
to have been met with. The great horn cores of the mountain sheep 
are occasionally to be seen bleaching among the clumps of sage bushes. 
Occasionally, also, the horns and bones of the bison are found, show- 
ing that southern Idaho was within the former range of that species. 
Besides the animals just mentioned, the plains are visited by bears, 
wolves, lynxes, foxes, skunks, etc., and the coyote is only too abun- 
dant. Ducks, geese, and other birds visit the occasional ponds and 
streams, particularly along Snake River and on the west side of the 
plain in the Lost River country. Grouse of several species are com- 
mon, and smaller birds are by no means rare. The life of the isolated 
timbered region referred to, and in fact of the Snake River Plains 
generally, has not been critically studied, and no doubt has many 
novelties with which to reward the naturalist. 
SOIL.« 
Although the soil of the Snake River Plains has well-marked varia- 
tions, it may be said that in general, and in fact almost everywhere, it 
is fertile and needs but the requisite moisture to enable it to produce 
a strong growth of either native or cultivated plants. So generally is 
the condition of the soil favorable to agriculture that it is easier to 
designate the exceptions than to describe the favored localities. About 
the border of the plains the material washed down by streams from 
the mountains is in numerous localities a coarse gravel, but although 
requiring much water when irrigated such land is not infertile. Over 
large areas the soil covering is thin and rock fragments are so numer- 
ous that under the most favorable conditions for irrigation the land 
could not be economically cultivated. Portions of the plains, too, are 
covered with recent lava on which practically no soil has accumulated. 
Examples of such black, rugged surfaces may be seen along the Oregon 
Short Line Railroad between American Falls and Minidoka, and again 
to the north of Shoshone, but the largest tract of recent lava occurs 
on the west side of the plains opposite Blackfoot, near the Cinder 
Buttes. Comparatively small areas of a similar character occur near 
Market Lake and between Big and Middle buttes. In the western 
portion of the Snake River Plains, south of Snake River, extensive 
areas of white lake beds are present, but are usually covered with 
yellowish, quartzite cobbles. Drifting sand occurs, particularly to the 
d See also pp. 135-141. 
