2<S FROM 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 caiion, where no difficulty presents itself in the way- of a favorable location. 

 The canon or gorge district is but twelve miles long ; there are about four localities where the 

 granitoid rocks impinge upon the stream in salient points, which will have to be 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 be attended by heavy gradua- 

 tion but in few instances — the average descent of the stream from the San Pedro to the western 

 limits of the caiion is about 14.5 feet per mile — and it is believed that no material increase of 

 gradient on this route will be required. From the mouth of the caiion to Camp G9 is thirty-nine 

 miles through the open valley, requiring but 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. 



