||24 IS UTAH SAHARA BOUND? It is well known that a soil protected by a dense cover of vegetation and a spongy mantle of organic matter not only maintains itself under the normal processes of geologic weathering, but grows, matures and stabilizes itself in a manner characteristic of the climate under which it is produced. Vegetation frequently stabilizes slopes at a steeper gradient than could possibly be maintained by a barren talus of the same rock material.2 Accelerated erosion begins when vegetation is reduced in density and when the normal litter and duff under it are disturbed. With the loss of vegetation and the top organic layer of soil, the bare earth is sifted by winds, splashed by raindrops and carried away by rivulets of water. The soil becomes puddled and its surface waterproofed. With the soil thus modified, water runs off rather than into it. New plants fail to take root and the vicious process of sheet and gully erosion proceeds with increasing acceleration. Thus the soil mantle that should serve as a natural reservoir for water and as a fountain source for our springs progressively fails us in holding back destructive storm run-off. It is sometimes argued-that a more rapid run-off from the watershed is actually beneficial, providing of course that the excess may be adequately stored in reservoirs. But rapid run-off almost invariably carries away increasingly great quantities of soil and sediments which inevitably must come to rest and displace the storage capacity of our reservoirs. When our reservoirs are filled with siltâ€"and good sites are rare in Utahâ€" what then? Anyone who takes false comfort in the theory of artificial water empoundage versus the natural detention of water within the soil mantle needs only to look at the north end of the Oquirrh Range where all vegetation has been killed by smelter smoke. The word "Oquirrh" is of Indian origin and means "wooded mountain." A hundred years ago the north end of the Oquirrh Range served as an important source of timber for the new settlement of Salt Lake City. The mountain slopes supported a lusli cover of vegetation, and clear water flowed north into the lake from Coon Canyon. At the turn of the century the $10,000,000 Garfield Smelter was established at the mouth of this beautiful canyon. Poisonous gases soon destroyed almost every vestige of spruce, maple and oak, and the canyon stream began to flow black with the accumulated top soil of ages. The most hideous defacement of the profiles of Nature to be found in Utah now stands there in mock contrast to the green beauty of this mountain 50 years ago. Floods have descended in such unabated fury that more than one-tenth of the value of this huge plant has already been expended in downstream engineering controls. In centuries to come when the Garfield Smelter will have been abandoned through the exhaustion of the mines that feed it, the north Oquirrhs will remain to posterity a cruel object lesson on the sin of mining biological resources.