MARICOPAS AND PIMAS PLAINS. 137 



Fig. 3 also represents the disposition of the Jornada viewed in section. 



Descending the eastern slope of these hills the plains of the Maricopas wells are reached. 

 These are flats on each side of the Gila, above its junction with the Salinas river. The river 

 flows through these plains, which are broad and well supplied with coarse grass. At the point 

 termed the Maricopas wells, which are several holes dug 7 feet down, and in which the water 

 rises within 2^ feet to the surface, the soil is clayey and retentive, each well being a small 

 body of -water resting on yellow clay ; when the well is emptied it fills in very slowly, the water 

 at this season being slightly saline. Tiie influence of this body of subterranean water is 

 marked by the difference of vegetation, which, as soon as the hill slope commences, ceases to 

 bear grass, rushes, canchalagua, and mesquite, and in their stead appear the fouquieria, 

 prickly pear, and pitahaya. The valley of the GrJla river is here very wide and the bottom a 

 fine sandy (granitic) clay, very light in color, and only fertile where watered by sequias of 

 the Pimas, when it produces abundantly. 



On each side of the river the Pimas cultivate the low land, wliere the sand and fine clay 

 has a darker tint, from the presence of a small quantity of humus ; it is, however, a mere trace, 

 and at the Maricopas wells is not more than half an inch thick, as shown by digging the fresh 

 soil near the springs. Portions of the soil of the cultivated land of the Pimas, and of the soil 

 upon the mesa, above the line of grass at the Maricopas wells, were collected and submitted to 

 chemical analysis ; the results are given in the chapter devoted to that purpose. There does 

 not appear to be any difi'erence between the mineral character of the two soils ; the texture 

 differs, that of the cultivated land being alluvial, and more quartzose. 



The cultivated ground of the Pimas is fenced around, each field being small, scarcely 150 feet 

 each way ; a sequia runs around half a dozen fields, giving off branches to each. Corn, cotton, 

 pumpkins, melons, and squash, were the chief articles of cultivation. A small portion only of 

 the valley is under cultivation, being that along the river bank ; but it is susceptible of 

 being made productive much further away from the stream. It is on irrigation only that a 

 secure crop can be depended on, and as the Grila has much less volume here than below, where 

 it receives the Salinas, occasionally the river bed is completely drained by the sequias. More 

 care and economy in the use of water would be necessary under a greater breadth of cultivation. 

 The immediate river bottom is here between six and eight miles across ; the mesa land is not 

 more than seven feet above this level, and slopes back, in every direction, very gradually to the 

 mountains, which are at six, eight, and twelve miles distance. The altitude of the Pimas lands 

 near their villages is a little above 1,100 feet above sea level, which, combined with the prox- 

 imity of long mountain masses, caused the deposition of dew at night, the first which had 

 been experienced since leaving Vallecitas ; it was quite copious when passing the Jornada to 

 reach these plains. 



Leaving the villages to the west, after a few miles travel, low spurs of a range coming in 

 from the southeast are met with. These consist of protogine and talcose slate ; on the north side 

 of one small hill, near the trail, fine-grained gneiss was observed, dipping 35° west ; still further 

 east the trail strikes the river twelve miles east of the villages. On the mesa the soil is a felspar 

 and granite debris ; near the river it is a fine sandy clay, similar to that of the Pimas lands. 



On the river, at this camp, (July 3,) the trails diverge ; the well-beaten ones are turning away 

 southeastward, over the elevated table land, which stretches out without any apparent limit 

 into Sonora, toward Tucson ; the uniform level being here and there only disturbed by an occa- 

 sional low hill of felspathic granite or protogine. Along these trails the wagons and main party 

 18 U 



