154: Soils of the Far ^Ye8t. 



1 2 3 i 



Soil (2) .". 10 36 34 22 



Acres. 

 San Luis Valley, Colo 3o, 776 



Rio Grande loam. — A sticky, plastic, black loam, containing con- 

 siderable gravel, resting on a subsoil of sand and gravel \vliicli 

 extends to undetermined depths. Soil contains considerable 

 organic matter. Found along small streams near the mountains 

 and in depressions. Formed partially from materials brought by 

 the streams from the mountains, and partially by the further 

 disintegration of the materials forming the San Luis sandy loam, 

 namely, lacustrine deposits of volcanic origin. The soil is very 

 difhcult to cultivate. When wet, it is a sticky mass of mud, and 

 when dry, it bakes similarly to the adobes of the Pacific coast. 

 It is not esteemed a very desirable soil for grain or alfalfa. At 

 present is used mainly for pasturage. The drainage is rather 

 poor and would be difficult to improve. 



12 3 4 



Soil (4) 10 23 36 31 



Acres. 

 San Luis Valley, Colo 23, 104 



MISCELLANEOUS SOILS OF THE FAR WEST. 



Salt River gravel. — Coarse gravel of undetermined depth. Bluff 



along Salt River, Arizona. Of no present agricultural value. 



Acres. 

 Salt River Valley, Ariz 1, 804 



Arroyo Seco sandy loam. — Dark-brown or yellowish coarse sandy 

 loam, containing a large percentage of coarse, well-rounded gravel 

 and small bowlders of granitic origin. Sometimes becoming com- 

 pact and very hard at surface. Found upon gently sloping fans. 

 Derived from stream wash from mountains. Somewhat deficient 

 in organic matter. Adapted to grains if well irrigated, but irriga- 

 tion is very difficult, on account of loss by seepage through coarse 

 subsoil. Yield fair in favorable seasons. Free from alkali. 



12 3 4 



Soil (2) 2it 36 23 12 



Acres. 



Lower Salinas Valley, Cal y, 670 



San Jose, Cal 7, 616 



