390 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



Charco Yuma. Here, near the villageless station of Rillito on the 

 Southern Pacific Railroad, a narrow strip of hind containing some 

 300 acres and extending along the raikoad for about 3 miles is culti- 

 vated by the stationmaster and a neighboring cattle rancher. "Talk 

 about dry farming," said the stationmaster, ''it's the easiest sort of 

 tiling. Five inches of rain a year is all we need here, and we get on 

 an average twelve. Just look at my fields. They're not so good as 

 usual, but they show what can be done in a bad year hke tliis. It's 

 aU in the way you plow and harrow and roll." A httle investigation, 

 however, sufficed to show that the 300 acres are supphed with very 

 effective irrigation, not artificial but natural. At tMs point moun- 

 tainous spurs cause the broad waste-filled basin of the Santa Cruz to 

 contract to a width of only a little over a mile. The rock floor of the 

 basin lies near the surface and acts as a concealed dam to raise the 

 level of the ground water. Also, the floods, when they come so far, 

 spread out here and accumulate in pools. Nevertheless the crop was 

 poor when I saw it because the rainfall of the winter of 1909-10 was 

 less than the average, and was badly (hstributed, most of it faffing 

 early in the winter. The grain planted in September and October 

 and even in early November grew fairly well, wliile that planted later 

 failed to head. Even in the best part of the 300 acres, however, that 

 is in the most moist depressions, the hay crop, for which the barley is 

 planted, was expected to amount to only about 15 tons as compared 

 with 95 in the preceding 3'ear. 



At least a quarter and probably a third of the winters durmg the 

 last 40 years, since records of precipitation began to be kept in the 

 region, have been even more unpropitious than 1909-10. If the 

 poor rainfall of that year could cause the diminution of the crops to 

 the extent of five-sixths, it requires no demonstration to show that 

 the fields must have been almost useless in the nine years since 1867 

 when the winter rainfall has been less than at that time. Outside of 

 the 300 acres now in use many attempts at cultivation have been 

 made near Charco Yuma, but without success. In years like 1904-5, 

 to be sure, with nearly 15 inches of winter rain between October and 

 April and 6 in the summer, from July to September, or like 1906-7 

 with nearly 8 in winter and 11 in summer, fine crops can be raised in 

 many places, but this is the exception, not the rule. 



To sum uj) the conditions at Charco Y'uma, it api)ears that no per- 

 manent supply of water is available without the diggmg of wells at 

 least 25 feet deep, a task liighly difficult for a primitive people mthout 

 iron tools. The nearest permanent supply of water is 8 miles away, 

 and even that occasionally fails. A period of two years and more 

 may pass without a smgle temporary flow of water. The total 

 amount of land capable of cultivation amounts to about 300 acres 

 sufficient to support 150 or 200 i)eople in ordinary years, but the 



