142 ABSAROKA DIVISION OF YELLOWSTONE FOREST RESERVE. 



known as "moss," scattered patches of GhrysotJiamnus and Artemisia shrubs, and 

 cacti. Where not so closely grazed a thin growth of grass comes up in the spring 

 and supiDlies pasturage for a month or two, after which nothing remains but close 

 stubble. The semiarid climate naturally brings about a low recuperative power in 

 the gramineous vegetation; and, with the excessive pasturing to which it long has 

 been subjected, its destruction has, from the first, been a logical result. 



Where the grassy turf has been at all extensive and completely destroyed there 

 has been gullying and denudation of the surface soil. Everywhere the "ditch," as 

 the lowest central depression in the canyon bottoms is aptly called, shows encroach- 

 ment on adjoining bench land or slope. It is clear that these waterways carry 

 larger volumes of water now during 'spring freshets than they formerly did, and 

 that their gullying power has correspondingly increased. The denudation of the 

 surface soil on the badly sheeped lands is especially marked on tracts situated in 

 the lower Deer and Work creeks drainage. Here the gullying of the soft soil on 

 the uplands, a sort of gumbo, is rapidly creating "bad lands." The result of the 

 destruction of the grassy turf on these plains is the same as from the destruction of 

 forest covers on mountain slopes — accelerated run-oflf, extensive and i-apid gullying, 

 and removal of the soil cover. 



WOODLANDS. 



A trifle more than 38 per cent of the quadrangle may be classed as woodland. 

 The largest proportion is situated in the northeast quarter on a tract 500 to 600 feet 

 above the average level of the nontimbered lands. Smaller tracts occur in the 

 southwest quarter, where they occupy a foothill region having an altitude of from 

 6,500 to 6,000 feet. Lesser areas fringe the larger streams in more or less con- 

 tinuous Unes. 



The woodlands are generally lightly stocked with timber. Limber pine, yellow 

 pine, red fir, and juniper, of the coniferous species, and aspen and cottonwood, of 

 the broad-leaved trees, are represented in the stockage. 



The lightly timbered conditions of these tracts are due to the many visitations 

 of fire which they have experienced during centuries, and to a naturally scanty 

 and defective seed production due to the arid climate. The stands are capable of 

 closer stockage, but to insure this result absolute freedom from fire and grazing is 

 necessary. Most of the timber has only a pole and fuel value. Less than 10 per 

 cent is mill timber, with only a 3-inch class value. The average yield of timber is 

 850 cubic feet per acre. 



The fringes of woodland along the streams are valuable only for fuel and 

 fencing material and, most of all, for the cohesion and waste-resisting power their 

 widely spreading roots impart to, the soft alluvium of the stream banks. 



