28 
PROM THE PIMAS VILLAGES TO THE RIO GRANDE. 
mile. Taking up this division in detail, we have, from the San Pedro, twelve miles of valley to 
the entrance of the canon, where no difficulty presents itself in the way of a favorable location. 
The canon or gorge district is hut twelve miles long ; there are about four localities where the 
granitoid rocks impinge upon the stream in salient points, which will have to he blasted off or 
pierced by boring short archways. At points intermediate to these salient spurs the denuded 
table lands, rounded and intersected by lateral arroyos, fill up the valley, affording a simple 
passage to the river. A location over these rolling slopes will not he attended by heavy gradua¬ 
tion hut in few instances—the average descent of the stream from the San Pedro to the western 
limits of the canon is about 14.5 feet per mile—and it is believed that no material increase of 
gradient on this route will he required. From the mouth of the canon to Camp 69 is thirty-nine 
miles through the open valley, requiring hut a grade of 11.5 feet per mile, with little or no earth 
work. From Camp 69 to the Maricopa wells, sixteen and three quarters miles, the Pimas plains 
are traversed with a descending grade of only 8.5 feet per mile. This portion of the division, 
like that immediately preceding it, will require very little more work than is necessary to adjust 
the sills securely for receiving the rails. 
