SAI^TA CEUZ TO TUCSON. 



19 



located the towns of Tubac and Tucson ; thence leading toward (though probably hardly ever 

 reaching) the Gila River, near the Pimo settlements. 



The situation of the town of Santa Cruz is highly picturesque, lying embosomed amid lofty 

 wooded mountains. Its soil is fertile, abundantly watered, and susceptible of easy irrigation ; 

 its elevation gives it a cool temperature, suited to the production of northern fruits and cereal 

 grains. 



A cut-off, over the mountain range intervening between the two courses of the river, leads, 

 by a distance of 18 miles, to a lower part of the valley, maintaining in the main the same gen- 

 eral features, but showing a marked change in the climate. This latter fact becomes still more 

 apparent in our progress downward, as shown by the comparative forwardness of vegetation. 

 Thus a short journey of three days (or 80 miles) from Santa Cruz, between February 27th and 

 March 1st, 1852, showed a difference in the advance of vegetation equal to a full month in time ; 

 so that while at Santa Cruz the cotton-wood trees were barely budding, the first day's journey 

 displayed their loose catkins, the second the opening leaf, and the third the full leaf. 



Greater aridity also characterizes the lower portion of the valley, and the live oik, so common 

 above, gives place to heavy growths of mezquite. The adjoining mountains on either hand 

 become in great measure bare of trees, and present steep ledges of igneous rock exposed along 

 their broken range. The immediate edges of the valley are flanked by a conglomerate forma- 

 tion, similar to that noticed on the Upper San Pedro. Accompanying these changes the stream 

 contracts, and finally, in certain points along its course, ceases to run, and the usual desert 

 features of all waterless tracts in this region are exhibited. 



"We thus pass the settlements of Tomocacori, Tubac, San Xavier, and Tucson, together with 

 numerous deserted ranchos occupying various points along the valley. After leaving Tubac, 

 which is situated about midway between Santa Cruz and Tucson, the valley expands into a wide 

 open basin, the mountains receding on either hand, and the dry valley, now almost exclusively 

 occupied by mesquite, is bordered by a wide stretch of gravelly table-land. On this table-land 

 we meet, for the first time on our route, that most remarkable vegetable production, the Cereus 

 giganteus. Further on it becomes abundant, its stiff trunks and branched arms rising up here 

 and there like sentinels, and giving a most peculiar character to the landscape scenery. 



Approaching the town of San Xavier, noted for its superb church, contrasting strangely with 

 the mud hovels surrounding it, we again come upon running water, with its constantly asso- 

 ciated fertility and verdure. In this vicinity occur rocky knolls, composed of a dark-colored 

 trap-rock, which formation becomes still more largely developed in the vicinity of Tucson, form- 

 ing extensive ridges having a tabulated form and very irregular outline. 



The settlement of Tucson occupies the lowest line of constant running water, and consequently 

 the last fertile basin lying in the course of this valley. Below this, on the north, succeeds the 

 extensive desert tract lying between Tucson and the Gila River. 



In pursuing our course down the valley, the adjoining table-land gradually merges into the 

 desert plain over which our road passes. Hardly, however, did it seem to deserve the name of 

 a desert at the time of our crossing it. Owing to the refreshing influence of recent rains, a 

 rapid growth of evanescent flowers gave its otherwise barren surface the aspect of a flower gar- 

 den, regaling both the sense of sight and of smell with a profuse and varied assemblage of tints 

 and scents. Water sufiicient for our animals was found in ravines by the side of the road, and 



