SECTION VI. 
From Flax River to Rio Colorado , 307.7 miles. 
It is much to he regretted that a greater length of time could not have been devoted to the 
examination of the region embraced in this section. It is full of interest, and probably no 
other portion of our territory would so richly recompense the cost and labor of a minute explo¬ 
ration. The region referred to is mainly included between the Gila and Colorada rivers, and 
their principal tributaries, Eio Verde and Flax river. The latter, having its sources in the 
Mogoyon and Zuhi regions, flows west and northwest to the Colorado, with which it is sup¬ 
posed to unite near the head of the celebrated Great Canon. Thence, the Colorado is said to 
course westward, through a fissure 1,500 feet below the surface of the vast plain that borders 
it, to the mouth of Eio Virgen ; there it turns south, and moves onward to the junction of 
Eio Gila. Eio Verde takes its rise near the San Francisco mountains, and, flowing south 
through fetile valleys, joins the Salinas and unites with Eio Gila near the Coco Maricopa vil¬ 
lages. The Gila forms the southern boundary of the area under consideration, which our line 
of survey intersects. It is traversed by several mountain chains of greater or less extent—of 
which the Hamook-liabi (Blue Eidge), Cerbat, Aquarius, Aztec, Black Forest, and Mogollon 
ranges are the principal—and dotted with many conical hills of volcanic origin. Between them 
are springs, streams, and valleys of considerable fertility. 
The northern portion of this area is believed to be an elevated table-land of the new-red sand¬ 
stone formation ; with strata slightly dipping towards the north-northeast, forming a region 
nearly as barren and waterless, upon the surface, as the celebrated Llano Estacado. Captain Sit- 
greaves traversed it in 1852, and from Camp 21 to Camp 26, a distance of 75 or 80 miles, no 
water was found. Near the parallel of 35° 15' the strata are broken ; and south of that line the 
upper portions are swept away, exposing “ magnesian limestone, sandstone of the coal measures, 
and the carboniferous limestone.” Still farther south, “ and especially at Pueblo creek, beds 
of. old-red sandstone are seen below the lower carboniferous, and in contact with the gneiss and 
granite, similar to the old-red of the Catskill mountains.”* Extending across this country, in 
a direction northeast and southwest, there is a series of volcanic cones indicating an axis of 
igneous eruptions. The San Francisco peaks, which are 5,000 feet above the base of the mount¬ 
ain, and 12,000 feet above the sea, appear to mark the point of greatest activity. Thence, the 
line of cones can be traced eastwardly across Flax river towards the Moqui country, and south¬ 
west so as to include Bill Williams’ mountain, Mount Hope, in the Aztec range, and Mount 
Ives and Artillery Peak, upon Williams’ river. Whatever may be the cause, the fact is evident 
that a large portion of the region south of the parallel of 35° 15' is well watered and fertile ; 
while that north of it is the reverse. Buins of ancient pueblos and evidences of former cultiva¬ 
tion are abundant throughout the valleys leading towards the Gila. The mountains and hills 
are covered with timber, the plains are variegated with patches of woodland and pasture, and 
the borders of the streams contain belts of arable soil. This country is capable of sustaining 
a considerable pastoral and agricultural population ; and, probably, the mines of silver and gold 
reported by the Spaniards and Indians as existing in the San Francisco and other mountains in 
the vicinity, and of which we saw indications, will add inducements to its settlement. 
West of the Aztec range the character of the country is considerably modified. The streams 
have generally a southwest course until they break through the beds of trap, lying upon the 
Q See the preliminary report rf .Tides Marcon. greolrglft to the expedition. 
