4 BULLETIN 615, U. S. DEPARTMENT OF AGRICULTURE. 



excessively heavy grazing. The farmer-stockman can not afford 

 to do without this feed. The temporarily larger profits that might 

 be derived from overgrazing would soon be offset by the somewhat 



more mock-rate but continued profits accrued from a stable stock 

 industry in which the lands are grazed on the basis of a sustained 

 yield. 



If instead of grazing merely one canyon beyond its carrying 

 capacity the entire forest unit, and, indeed, all forest land of irregu- 

 lar topography throughout the West were likewise grazed, untold 

 injury to farm land and other property from destructive erosion and 

 floods would result, a sustained stream flow would no longer exist 

 on the watersheds, and there would be neither a normal supply of 

 water for the irrigation of the adjoining farm lands nor of forage for 

 the live stock on the extensive forest ranges. Without these produc- 

 tive elevated range lands upon which to summer the stock, homes on 

 ;iy farms could no longer be maintained; and it would not be 

 long before the lands would revert to the original wild state. 



Within the boundaries of the Manti National Forest of Utah there 

 is a belt of approximately 47,000 acres of land along the east side 

 of the divide which is badly depleted as a result of overgrazing and 

 erosion, making necessary a regulation protecting* the areas from 

 grazing part of the year. Along the west side of the divide there is 

 a. similar belt of about the same acreage where erosion is also causing 

 damage. These belts are practically timberless, and are of value 

 chiefly as watersheds, from wdiich stream flow for irrigation is sup- 

 plied, and for the grazing resources which they afford. That these 

 and similar eroded lands would originally support a cow or the 

 equivalent in sheep on from one-third to one-fifth the acreage re- 

 quired at the present time is evidence of the enormous loss annually 

 to the live-stock industry alone. The soil and plant foods on these 

 already relatively unproductive lands continue to be carried away 

 by the run-off following each storm ; and the destruction, where well 

 advanced, is sure to continue until preventive measures are fully 

 established. 



Typical instances of the damage caused by erratic run-off and 

 erosion are well worth citing. On July 28, 1912, a rainstorm oc- 

 curred at the head of Ephraim Canyon, on the Manti National 

 Forest, within a belt of 2 miles and between elevations of 9,000 and 

 10, 500 feet. There was no rain in the valley or on the mountain 

 below, approximately, 8,000 feet. The storm of 0.41 of an inch of 

 rain fell intermittently, but at no time with special violence, for a 

 period of two hours. A flood of sufficient force developed to reach 

 to the city of Ephraim, 10 miles below, covering the streets and some 

 farm hind, and filling the basements of buildings with mud and 

 debris. Laden with silt, logs, vegetable matter, and, during the 



