APPENDICES. 59% 
D. 
Official Report of the Survey of the River Gila, by Lieu- 
tenant A. W. Whipple, of the Topographical Engineers, 
dated San Diego, California, January 10th, 1852. 
San Dingo, Carirornta, 
January 10th, 1852. 
Cot.: I have the honor to report my arrival at San Diego, with 
the party of the Boundary Commission under my command. Nearly 
the whole time since you left us upon the San Pedro, until our arrival 
here, we have been upon a short allowance of provisions. 
With fourteen and a half days’ rations of flour, and without an 
escort, we left St. Peter’s Springs upon the Rio San Pedro, on the 3d of 
October, 1851. We arrived at the desired points on the Gila, north- 
east of Fort Graham, on the evening of the 9th. The transit instrument 
was mounted the same night, and both limbs of the moon were observed 
for longitude. The Topographical survey of the Gila, was commenced 
at this point. My excellent assistants in this portion of the work, Henry 
C. Force and Frank Wheaton, are worthy of great praise for their indus- 
try and skill in the performance of their duties. I should be pleased to 
have their names brought before the Department at Washington, and 
their merits appreciated. 
The survey was carried on without difficulty below the junction of 
Rio San Francisco, as far as the entrance to the cafion of the Pinal 
Llefio mountains. Into this we forced our way, although Indians told 
us that neither man nor beast could pass through. In some places by 
wading, in others by climbing upon the sides of the cafion, which rose 
perpendicularly from five to fifteen hundred feet m height, the survey 
progressed for eight or ten miles. The want of men and of provisions 
prevented us from sending reconnoitering parties in advance. The train 
passed over mountains rough and steep upon the north side of the river. 
Having succeeded in reaching a gorge by which a mountain stream 
leaps into the river, we were here compelled to abandon our wagon and 
lead the pack-mules over steep mountains. The following extract from 
the Meteorological Notes, will give an idea of our route. 
