FOR A RAILWAY. 569 
river ; but they are passed by following the valley of the river 
or other openings through them. 
No stream enters the Gila on the south side after the San 
Pedro is passed. ‘There is a small water-course known as the 
Santa Cruz River, which rises im some springs near the sources 
of the San Pedro, and which, after a course of less than a 
hundred miles, is lost in the desert near Tucson. Near this 
are good lands, which by irrigation are rendered fertile. We 
have, therefore, a space of about two hundred and fifty miles 
without a water-course or arable valley except the Santa Cruz, 
and nearly one hundred and sixty miles before any consider- 
able stream is reached at the south, in the State of Sonora. 
This wide region is of the most barren and desert-like character, 
consisting of arid plains, with short and detached ridges of 
mountains at Jong intervals. 
The water-courses of Sonora take their rise in the Sierra 
Madre and in the mountains at the north. Those which rise 
in the former, receiving a more copious and constant supply of 
water, reach the ocean ; while the streams in the northern por- 
tion of the State, after traversing arid deserts, and forcing 
their way through lofty mountains for three or four hundred 
miles, lose so much by evaporation that they do not reach the 
sea, but are swallowed up in the sands of the desert or cvene- 
gas (marshes). These streams lose much, too, by irrigating 
the cultivated valleys through which they run. 
Hixcept along the bottom-lands of these streams, there is 
no arable land in Sonora. What there is, however, is exceed- 
ingly fertile, and yields enormous crops. Owing to the rapid 
descent of the streams, the water is easily controlled and con- 
ducted by irrigating canals over the arable lands; so that 
every considerable land-owner may have his own canals. In 
the northern portion of the State, near the Gila, there is but 
little tillable land. The best portion of it is that occupied by 
the Pimo and Coco-Maricopa Indians. In portions of the 
Santa Cruz and San Pedro valleys are good lands, but the 
