Big sagebrush, locally known as black sage or blue sage, and often 

 called simply sage or sagebrush, is a large deciduous shrub with 

 silvery green leaves. It is one of the most widespread and most fa- 

 miliar species of Artemisia, in addition to being probably the most 

 abundant shrub in western North America. 1 The specific name 

 tridentata refers to the three teeth at the apex of the leaf. The 

 species ranges from western Nebraska to Montana, British Columbia, 

 eastern California, Lower California, and northern New Mexico. 

 Big sagebrush occurs as a major part of the plant cover over vast 

 areas of the semiarid lands of the West, ranging in altitude from 

 about 3,000 feet in Oregon and 3,300 feet in Montana to timberline 

 in the mountains of Colorado. However, it grows most abundantly 

 on the valley bottoms, plains, foothills, and mesas up to about 8,000 

 feet, occupying much of the semidesert lands throughout the Inter- 

 mountain region and northward through Wyoming, Idaho, eastern 

 Oregon, and eastern Washington. It usually appears in open stands, 

 frequently covering great expanses of country with a dense gray 

 mantle, which is often referred to in ecological literature as the 

 "Northern Desert Shrub Formation." Because of continued over- 

 grazing, with the resultant death or decimation of the valuable 

 perennial bunchgrasses, vast areas of western range contain almost 

 pure stands of this species. 



Big sagebrush grows on a variety of soils, from the shallow rocky 

 loams of foothills and slopes to the vast areas of disintegrated lava 

 formations in the Snake River plains of Idaho and eastern Oregon, 

 but seldom occurs abundantly on soils of granitic origin. In north- 

 ern Nevada and Utah it principally inhabits the rich limestone 

 soils of the valleys and foothills. This species grows most typically 

 and luxuriantly with wheatgrasses, bluegrasses, rabbitbrushes, and 

 snakeweed on the deep, well-drained alluvial clay loams at the foot 

 of the main mountain slopes. In the open ponderosa pine, oak 

 brush, and pinon- juniper belts it ordinarily appears in association 

 with wheatgrasses, snowberries, lanceleaf yellowbrush, serviceber- 

 ries, and needlegrasses. This plant thrives best on rather light, 

 pervious, well-drained, alkali-free soils having a good water supply, 

 as its deep roots facilitate utilization of water that percolates to 

 considerable depths. Big sagebrush is frequently killed by flooding 

 or by the rise of the water table above the subsoil horizon. Tall, 

 dense stands of the plant are indicative of fertile soil suitable for 

 small grains and adapted for irrigated farming. 



Observations by Clements 2 indicate that, although big sagebrush 

 apparently is the dominant plant throughout much of its range, it 

 is now truly climax only on approximately one-fourth (the driest 

 portions) of its present area. Elsewhere it has invaded former 

 grasslands which have been depleted by overuse. The current agri- 

 cultural lands of the West were developed from the fertile, grassy, 

 big sagebrush areas of former years. 



At the outset grazing in the Intermountain region was centralized 

 near settlements. As a direct result the neighboring grassy sage- 



1 Dayton, W. A. IMPORTANT WESTERN BROWSE PLANTS. U. S. Dept. Agr. Misc. Pub. 

 101, 214 pp., illus. 1931. 



2 Clements, F. E. THE RELICT METHOD IN DYNAMIC ECOLOGY. Jour. Ecology [London] 

 22 (1) : 1-68, illus. 1934. 



