SUMMARY. 25 



Alamosa is the principal town. Transportation is afforded by 

 several lines of the Denver & Rio Grande Railroad. 



The climate is healthful and favorable to the production of grains, 

 grasses, legumes, and certain vegetables. The annual rainfall is 

 about 8 inches. Cold winters, short summers with cool nights, many 

 sunshiny days, and a low relative humidity are salient climatic 

 features. 



The valley is flat and treeless. The soils of the foot slopes and 

 alluvial fans are of porous, sandy, and gravelly character, underlain 

 by leachy, gravelly subsoils. The alluvial soils of the valley floor and 

 tributary stream bottoms are of darker color, heavier texture, and 

 more compact structure. Those of the valley floor sometimes occupy 

 poorly drained flats subject to overflow. 



The prevailing soils of the marginal slopes are included in the 

 San Luis series. They are gravelly sand, sandy loam, or loam, and 

 derived mainly from volcanic rocks. The surface is well adapted to 

 irrigation. The soils are usually easily cultivated, but are leachy 

 and not retentive of moisture. Lower lying slopes and depressions 

 suffer from seepage water and alkali. 



The alluvial soils of the stream bottoms are usually sandy loams, 

 loams, or clay loams, underlain by gravelly subsoils. They are more 

 retentive of moisture than the soils of the Rio Grande series, but 

 not so well drained. Accumulation of seepage water and alkali in 

 places causes considerable injury, but otherwise they are well adapted 

 to grains, alfalfa, grasses, field peas, and vegetables, including the 

 root crops. 



The northern and central parts of the valley contain small areas 

 of the gravelly foot-slope soils. The alluvial soils and intermediate 

 types cover more extensive areas, while the central and eastern parts 

 of the valley contain large areas of wind-drifted sands ; broken by 

 low flats without drainage and occupied in places by alkali lakes. 



Very little desirable public land remains subject to entry, but 

 partially improved lands suitable for farming may be purchased at 

 moderate prices. 



The available supply of water for irrigation by gravity systems 

 is inadequate, but the area served might be increased by less wasteful 

 methods of distribution and use. Storage reservoirs may in the 

 future relieve conditions, but are not favored by present circum- 

 stances. 



The prevailing method of applying water is by subirrigation. 

 This system is wasteful, is not adapted to the soils of the San Luis 

 series or other porous, gravelly types, and has resulted in wide- 

 spread damage to lands upon lower slopes through the water-logging 

 of the subsoils and the accumulation of alkali. 



