ranges of Nevada and Utah, and the Colorado Pla- 

 teaus of Arizona. Associated with the many species of 

 sagebrush are wheatgrasses, fescues, bluegrasses and 

 bromes, and broadleaved forbs, all well adapted to 

 the harsh climatic conditions of the area. 



Generally south of the sagebrush ecosystem (but 

 interspersed with it in Nevada) lie some 50 million 

 acres of two forest ecosystems often grouped with range — 

 pinyon-juniper and chaparral-mountain shrub. The 

 pinyon-juniper ecosystem, the so-called pygmy forest 

 of the Southwest, is characterized by juniper and 

 pinyon pine growing as open to dense woodlands or 

 savannas. Understory vegetation of wheatgrasses, 

 Indian ricegrass, gramas, and shrubs such as moun- 

 tain mahogany, sagebrush, and rabbitbrush, depends 

 to a large extent upon the density of the crown can- 

 opy. Intermingled with and below the pinyon-juniper 

 lies the main portion of the chaparral ecosystem. 

 Dense-to-open stands of deciduous and evergreen 

 low trees and shrubs occupy the lower flanks of the 

 mountains in Nevada, Utah, and Arizona. Principal 

 trees are alligator and one-seeded junipers and several 

 evergreen oaks. Shrubs such as manzanita, cliff-rose, 

 ceanothus, Apache plume, and silktassel, sometimes 

 form stands so dense that herbaceous vegetation is 

 absent. The acreage in this ecosystem has been 

 reduced in the southwest through clearing to increase 

 forage yields. 



Below the pinyon-juniper and the chaparral on 

 even more arid sites, are 80 million acres of the desert 

 shrub and desert grassland ecosystems. Desert shrubs 

 vary from a few inches to several feet tall, and are 

 generally in open stands interspersed among areas of 

 bare soil and rock pavement. Mesquite and acacia are 

 low-growing trees present in the ecosystem. Black- 

 brush, creosote bush, palo verde, jojoba, prickly pear, 

 choUa, and other cactuses form open to very dense 

 shrub stands. Herbaceous species are mostly absent 

 except in the years of high winter and spring mois- 

 ture. In such years, forbs that have been unseen for 

 many years will form bright carpets of color. 



The dry desert grassland ecosystems occur on 

 tablelands in Arizona, New Mexico, and Utah. Vege- 

 tation is predominantly grass with blue grama, gal- 

 leta, and tabosa being the most common. Shrubs are 

 few and forbs generally not prominent except in the 

 occasional years of abundant rainfall. 



The rangelands of the Rocky Mountains and Great 

 Plains support the Nation's range cattle and sheep 

 industries. Cow-calf operations based here provide 

 many of the beef cattle that eventually pass through 

 feedlots on their way to packing plants and to the 

 Nation's tables. These rangelands also support wild 

 horses and burros, antelope, deer, and bighorn sheep, 

 and provide winter range for elk. 



The role of the rangelands in the Rocky Mountains 

 and Great Plains in providing outdoor recreation 

 opportunities varies because of the great variation in 

 the lands themselves. Mountain meadows and alpine 

 areas are used for primitive and wilderness camping. 

 Off-road vehicle excursions are common over desert 

 and semi-desert areas. 



Established wilderness areas in the Rocky Moun- 

 tains include some rangelands, especially the moun- 

 tain meadows in the Rocky Mountain States. How- 

 ever, there are few untouched remnants of the 

 rangelands in the Great Plains, and little has been 

 done to protect examples of desert rangeland types. 

 Desert rangelands are likely to receive consideration 

 in the near future as the Bureau of Land Management 

 prepares an inventory of potential wilderness areas 

 on lands it administers. 



Ownership — About 58 percent of the rangeland 

 area in the Rocky Mountains and Great Plains is in 

 non-Federal ownership (table 2.3). In the Great 

 Plains States, 95 percent of the rangeland is in non- 

 Federal ownership; but 50 percent is Federally owned 

 in the Rocky Mountain States. The Forest Service 

 administers 7 percent of the rangeland in the section; 

 the Bureau of Land Management, 30 percent; and the 

 other Federal agencies, only 4 percent. In Nevada, 

 the Federal agencies administer 92 percent of all 

 rangelands. 



Productivity — Productivity of the rangeland eco- 

 systems in the Rocky Mountains and Great Plains is 

 highly variable. The grassland and prairie ecosystems 

 of the Great Plains produce on the average 1,000 to 

 3,000 pounds of herbage and browse per year (table 

 2.6). On the better sites, they will yield as much as 

 7,000 pounds per acre. In the rest of the section, only 

 the mountain meadows average better than a ton of 

 herbage and browse per acre. Except for sagebrush 

 and chaparral-mountain shrub, the arid and semi- 

 arid ecosystems of the Southwest produce only small 

 amounts of herbage and browse, averaging well 

 below a half ton. The sagebrush and chaparral 

 ecosystems will average from 1,000 to 2,000 pounds 

 per acre, with as much as 3,000 pounds on the best 

 sites. 



Water Areas 



The Rocky Mountains and Great Plains section is 

 the driest in the country in terms of rainfall. And it 

 has the smallest water area — in absolute as well as 

 relative terms — of all of the sections. The total water 

 acreage — all inland water — is 9.3 million acres, 

 slightly more than 1 percent of the total area (table 

 2.1). The largest concentrations of water are in Utah, 

 Montana, North and South Dakota. 



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