Ch. 23] LAND MISUSE 421 



ties prior to range depletion is shown by Woolley (1946, p. 87), who 

 lists the occurrence of four floods in Utah by 1854, only 7 years after 

 the arrival of the first pioneers. Two of the floods carried immense 

 quantities of debris and mud, indicating advanced erosion even under 

 practically virgin range conditions. 



The most serious criticism of attributing recent cutting exclusively 

 to overgrazing is that it fails completely as an explanation for earlier 

 periods of erosion which occurred long before the area was disturbed 

 by the white man's herds. Hack (1942), Sayles and Antevs (1941), 

 Albritton and Bryan (1939), and Bryan (1926) have described the 

 evidence of such previous erosion at various localities in the South- 

 west. The writer has found similar evidence in the San Simon Wash of 

 Arizona previously mentioned. The numerous filled channels that can 

 be found outlined in the banks of most existing gullies are also con- 

 sidered positive indications of former gully systems at least approach- 

 ing the present ones in depth and extent. 



Overgrazing, as a prerequisite to erosion, likewise fails to explain the 

 occurrence of erosion in areas that have never been used. Gregory 

 calls attention to such occurrences in the Navajo Reservation (Greg- 

 ory, 1917, p. 132). The writer has observed a similar condition in the 

 Fort Bayard Military Reservation, New Mexico, where reportedly 

 grazing has been excluded or rigidly controlled during the last several 

 decades (Fig. 4c) . Similarly an inconsistency is apparent in the con- 

 dition found in many valleys, where certain portions have cut while 

 other parts have not, although all have been subjected to the same 

 grazing use. In the San Simon Valley, for instance, only a few of 

 the main tributaries are gullied, although the others have obviously 

 been subjected to equal, if not more intense, grazing. 



The literature on conservation is replete with descriptions of the 

 deterioration of the western ranges that has occurred since livestock 

 arrival, and most of it is based on the premise that stock alone has 

 been responsible for the depletion (see especially Bailey, 1935 ; Cooper- 

 ider and Hendricks, 1937; Forsling, 1931; Bailey et al., 1934; Cottam, 

 1947). Much stress is placed on the descriptions of early explorers, 

 who picture lush grass in contrast to the present barren conditions. 

 These, however, can be considered fair comparisons only when they 

 are made with due regard to precipitation experienced in the contrast- 

 ing years. Occasional seasons of favorable rainfall still produce a 

 cover approaching that described in the earlier accounts. That there 

 has been a general deterioration is conceded, but the proof is not yet 

 positive that it can be attributed to the effects of overgrazing alone. 



