294 FORREST SHREVE 



of the bajada slopes extend to within 3 miles of the river, and 

 in many cases their slender ends have been cut away from the 

 main bajada, now appearing as elliptica hills with steep sides 

 and flat tops, which still show an inclination accordant with 

 that of the main bajada (see fig. 2). The inclination of the 

 bajada surfaces is such that the innermost portions, next the 

 mountain, are about 1000 feet higher than the ends nearest 

 the river. The gradient of the streams as they follow the inter- 

 bajadal valleys is much less than this. The line of contact 

 between the true base of the mountain and the summits of the 



Fig. 2. Looking toward the Gila River from the northeastern base of the 

 Pinaleno Mountains, showing the dissected bajada at the right, and in the center 

 a hill of bajadal origin. 



bajadas is now almost invariably occupied by shallow drainage- 

 ways of relatively recent origin, or in a few cases is occupied 

 by a major streamway. 



On the southwestern side of the mountain the largest streams 

 reach the plain and quickly disappear, with almost no evidences 

 of the history of the enormous amount of deposition that must 

 have been taking place. There is abundant evidence that these 

 streams have frequently changed their courses in the immediate 

 vicinity of the mouths of their canons, but the boulder-strewn 



