Adams] SHONTO: ROLE OF NAVAHO TRADER 35 



the Shonto Plateau which is formed by downwash from Black Mesa, 

 and overlies the Navaho Sandstone. It is constituted of the heavy- 

 blue adobe, familiar to travelers in the northern Southwest, which re- 

 sults from the decomposition of Mancos Shale on the side of the mesa 

 above. Klethla Valley exhibits the typical pattern of gully erosion 

 found in adobe soils everywhere, and is totally unlike any other por- 

 tion of the Shonto area. 



WATEB SUPPLY 



Permanent surface streams occur only in Tsegi Canyon and the 

 upper reaches of Shonto Canyon. Elsewhere, drainage is intermit- 

 tent, but the rock bottoms in most watercourses permit a maximum of 

 conservation in small pools, waterpockets, and impounds. Supple- 

 mentary water supply comes from a couple of small dams in Cow 

 Springs Canyon and from numerous stock tanks on the plateau. 

 There are, in addition, four deep wells, with the conventional windmill 

 pumps, in various parts of the area. Shonto Trading Post, with its 

 electric pump and unfailing water supply, is the most important smgle 

 water source in the Shonto area. 



VEGETATION 



Vegetation varies with altitude, as ui the Colorado Plateau gen- 

 erally. The lowest portions of the Shonto area, in the south, sup- 

 port only a cover of bunchgrasses — principally gramma — and hardy 

 shrubs, prominent among which is Mormon tea. At about 6,500 feet 

 elevation, the complex is joined by a dense growth of sagebrush which 

 covers the greater part of the Shonto area, extending upward to about 

 8,000 feet. With sagebrush comes a scattered growth of juniper, which 

 is augmented by pinyon at a slightly higher elevation. In the vi- 

 cinity of Shonto itself, the country presents a savannalike appear- 

 ance, with pifion, juniper and oak clustered densely along ridges and 

 slopes, and open stretches of sagebrush and tall grass in between. 

 A little farther north, the woody cover becomes dense, extending to 

 the northern limits of the Shonto area. At its extreme upper end, 

 juniper has ceased, but the heavy stand of large piiions is aug- 

 mented by a few Ponderosa pine and two small groves of aspen, 

 as well as numerous thickets of Gambel's oak. 



Watercourses exhibit, in addition, willow and numerous woody 

 shrubs. Cottonwoods have been planted in Cow Springs and Shonto 

 Canyons, and occur near springs in one or two other places. 



CLIMATE 



Meteorological records have been kept for several years at Navajo 

 National Monimient (Betatakin), within the Shonto area. A 10- 

 year average, from 1940 to 1950, reveals a mean annual temperature 

 of 49.9°, with extreme monthly means of 71.9° in July and 29.6° in 



