HEWETT] RIO GRANDE VALLEY, NEW MEXICO 19 



precipitation reaches 25 inches iji the higher mountains. Precipi- 

 tation is unequally distributed throughout- the year. Heavy rain- 

 falls of a few hours' to some days' duration are followed by months 

 devoid of moisture. The effects of rainfall disappear rapidly because 

 of the character of the soil and the atmosphere. The range of tem- 

 perature is considerable, owing to the great range in altitude. The 

 nights are mvariably cool, even in summer. There is little zero 

 weather ui whiter except m the high altitutles, and oppressive days 

 in summer are unknown even in the lower valleys. This is due not 

 so much to absence of heat (for at midday there may be a scorch- 

 mg temperature) a^s to lack of humidity. Sultry, nmggy days are 

 unknown. The season for crops varies m length with the altitude, 

 but is rather short at best. Small grain thrives even in the highest 

 valleys, while fruit-growing is limited to areas below 7,000 feet. 

 Various grasses flourish up to the highest altitudes. Corn matures 

 in the valleys and on the mesas up to 8,000 feet. This crop, while 

 an exceedingly meager one m comparison with the prolific yield of 

 the Middle West, has been very influential m determining the 

 aboriginal culture that developed hei'e. 



The country is poor in natural food products. In the canyons a 

 few berries, wild cherries, and wild plums are found. Certain species 

 of oak furnish acorns in quantities sufficient for food, and the nuts 

 of the piiion (Pinus edulis) are used by the Indians and Mexicans. 

 There are some food fish in the Rio Grande and trout in the mountain 

 streams, but the Pueblo Indians fish but little. Game is scarce. 

 Deer are more rare than in the northern part of New England. Bears 

 are occg,sionally found in the mountain canyons. Coyotes, tmiber 

 wolves, wildcats, pumas (mountain lions), and squirrels exist, but not 

 in large numbers. There are some wild turkeys in the forests, but in 

 general birds are rare. The rattlesnake is the only reptile that is 

 numerous, and this in only a few places, notably in the White Rock 

 canyon between Buckman station and the mouth of the Rito de los 

 Frijoles. In marked contrast to the poverty of vertebrate life is the 

 extreme richness of the insect faima. At certain seasons butterflies 

 ap]>ear in the valleys in vast numbers. There are many species of 

 wild bees. Occasionally swarms of locusts appear and these are 

 greatly prized by the Pueblo Indians for fot)d. Tarantulas and centi- 

 pedes occur, but not so ]>leiitifully as on the plains east of the Rocky 

 mountains. There are lizards in almost endless A^ariety, and great 

 numbers of bats frequent the ancient clift' houses of the plateau area. 



The method of mesa building seen in the Rio Grande valley points 

 to a former climatic condition radically different from that which now 

 prevails m the vSouthwest. The sudden heavy downpour of rain now 

 characteristic of this region sweeps large quantities of gravel and silt 

 from the mountain sides into the gulches and on into the river basms, 



