INCREASING FORAGE YIELDS ON INTERMOUNTAIN WINTER RANGES 9 
shadscale is mixed with grasses and other shrubs. Wherever grazing 
has been excessive, on mixed shadscale-winterfat-grass ranges, the 
palatable grasses and winterfat (‘‘whitesage”’) have often been sup- 
planted by shadscale, which is protected from excessive grazing by 
sharp thorns. 
F-260665 
Figure 6.—Small rabbitbrush type (left) merging into winterfat type (right). Plant 
types are usually dominated by one or two plants, and lines of demarcation between 
them are often distinct. 
Two subtypes containing shadscale cover almost half of the Desert 
Experimental Range. The shadscale-grass subtype occupies 14,276 
acres and the shadscale-winterfat-grass is found on 12,687 acres (fig. 7). 
When the grass within the subtype is primarily a single species, it is 
listed in the subtype designation. For example, where Indian rice- 
grass is a major species, the shadscale-grass subtype is often called the 
shadscale-Indian ricegrass subtype. Shadscale in pure stands occupies 
areas on the experimental range too small to map, although it is ex- 
tensive on the general winter range. 
The type dominated by winterfat is probably the second most ex- 
tensive found on the winter range. Subtypes of almost pure winterfat 
exist on the deep, fine, alluvial soils near the valley bottoms and in the 
broad, fairly level drainages where runoff from summer storms ac- 
cumulates. On the higher valley slopes, winterfat grows in mixture 
with other species. These mixed subtypes furnish excellent forage for 
sheep, especially if the associated species include Indian ricegrass or 
black sagebrush. The winterfat type is represented on the experimental 
range by two subtypes: Winterfat-small rabbitbrush-grass, 5,132 acres; 
and pure winterfat, 3,949 acres. 
Plant types dominated by mat and Gardner saltbushes are not widely 
distributed within the Intermountain region; but on localized areas in 
eastern Utah and southwestern Wyoming they are extensive enough to 
be important. They are usually found in almost pure stands on the 
lower valley slopes and level soils of the valley bottoms, which oc- 
casionally receive runoff from melting snows or summer storms. Types 
containing these saltbushes furnish excellent winter forage for sheep. 
