BIG TIMBER QUADEANGLE. 141 



to the south. This tract is roughly sculptured, its areas being a succession of steep, 

 narrow ridges and deep, rocky canyons. 



The average altitude of, the plateau region is 4,800 feet; in some localities 

 projecting points rise 600 to 600 feet higher, while in the northeast quarter alone the 

 average elevation slightly exceeds 6,000 feet. The average altitude of the mountain 

 areas in the southwest quarter is 6,800 feet, with here and there points which reach 

 elevations of 7,500 feet. 



DRAINAGE CONDITIONS. 



The quadrangle lies wholly within the drainage of Yellowstone River. While 

 a large volume of water is carried by the different streams in the district, only a 

 trifling proportion originates on its areas. Most of the different canyons and 

 ravines are drj"^ during summer and fall, carrying water only while the spring 

 break-up lasts, or immediately^ after heavy rainstorms. Springs are not plentiful 

 outside the mountain areas in the southwest corner of the district, and the few 

 standing bodies of water here and there are mere pools. 



AGRICULTURAL LANDS. 



The agricultural lands comprise between 6 and 7 per cent of the quadrangle 

 and are confined to the lowest terraces bordering Yellowstone River and the other 

 larger streams. Irrigation is practically indispensable, and the lands most easily 

 and least expensively irrigable have been reclaimed first. With high-line ditches, 

 possible in many localities, a large portion of the area now utilized as range land 

 can be reclaimed. 



The soil in the valleys consists of a deep, rich, more or less alkaline soil, 

 yielding good crops of grain, and hay. The uplands are often stony and bowlder 

 strewn, particularly in the southern half of the^quadrangle, where a great deal of 

 glacial bowlder and gravel drift was deposited during the glaciation of the high 

 Absaroka ranges to the south. 



GRAZING LANDS. 



The range lands comprise very nearly 48 per cent of the lands in the quadrangle, 

 and including the woodlands, utilized as pasture ground, amount to 85 per cent. 

 Originally the lands were covered with good growths of various sorts of grasses, 

 but for many years the region has been closely ranged by cattle and sheep. Outside 

 inclosed tracts the condition of these range lands is now in general exceedingly bad, 

 owing to excessive pasturing, but more particularly sheeping. In many instances, 

 especially in the south half of the quadrangle, every vestige of gramineous vegeta- 

 tion has been either eaten or trampled out hy sheep. Nothing remains but small 

 patches of the common, indigenous phlox, so low and scanty that it is locally 



