rxjssell.] CLIMATE AND VEGETATION. V 
the valleys, there is but one mountain range in the region on which 
it remains throughout the year. On Stein Mountain, Oregon, snow 
banks occur in the shelter of northward-facing cliffs in midsummer, 
and severe snowstorms occur as late as the first week in July and as 
early in the autumn as the middle of September. It is principally 
the melting of the usually abundant snow on this mountain range 
that feeds the many streams which flow from it into the adjacent 
valleys. 
On account of the small rainfall in the valleys, agriculture is 
impracticable without irrigation. Throughout much of the region 
agricultural pursuits are restricted also on account of the liability of 
frost, particularly in the more elevated valleys where other conditions, 
such as the composition and texture of the soil are favorable. 
At one time both valleys and mountains throughout southern 
Idaho and adjacent portions of Oregon were clothed with nutritious 
bunch grass, but now to a great extent these natural pastures are 
nearly ruined, owing to overgrazing. The valleys are treeless, except 
for the occasional cottonwoods along the immediate margins of 
streams, and the hills and lower mountain slopes are for the most 
part devoid of timber. 
Throughout southern Idaho and over the greater portion of Oregon 
east of the Cascade Mountains, the plant which is most characteristic 
is the sagebrush (Artemisia). In common with nearly all of the arid 
region of the United States, the area discussed is a sagebrush land. 
At no locality along the route traveled is one beyond recognizable 
distance of this ubiquitous grayish-green shrub, except while cross- 
ing the barren mud plains left by the desiccation of ephemeral lakes 
or while standing on the summit of Stein Mountain. Although the 
sagebrush imparts a dreary monotony to the valley and lower 
mountain slopes, every traveler who lives out of doors is indebted to 
it for fuel. Not only does the sage replenish the explorer's camp 
fire, but to a considerable extent it is the ranchman's wood pile. 
Where it grows sturdily there is rich land, which needs only irriga- 
tion to make it highly productive. 
The first tree to make its appearance when increase in elevation 
brings about greater precipitation is the juniper. Mingled with the 
scattered juniper trees, and usually beginning at a somewhat greater 
elevation than their lower limit, are thickets and groves of mountain 
mahogany. These grayish-green trees when growing wide apart fre- 
quently attain a height of 20 to 30 feet and look not unlike olive 
trees. They add much to the beauty of the land, or, perhaps more 
accurately, detract in a marked way from the desolation of the lower 
mountain slopes. In the deep stream-cut valleys they frequently 
form almost impenetrable thickets. On many of the lower mountains, 
as Mahogany Mountain in Oregon, for example, they constitute almost 
the only arboreal vegetation. Above the lower limit of the juniper 
