26 EXTRACTS FROM [PRELIMINARY] REPORT. 
the Puerco of the West the route continues down the Colorado Chiquito for seventy-five miles, 
with an average descent of only six feet per mile, thence striking west to the pass south of the 
San Francisco mountain. By the route surveyed the distance from the river to this pass is 
forty-two miles, with grades of forty, forty-six, and forty-five feet per mile. By leaving the 
Colorado Chiquito further east than the point of survey, this grade may he materially modified. 
Passing this summit, the route continues west for thirty miles over an undulating region north 
of Bill Williams’ mountain, through thick pine forests, with undulating hut descending grades, 
the maximum being about thirty feet per mile. Here a small summit is passed which divides 
the waters of the San Francisco from those flowing northwesterly towards the Little and Great 
Colorado. With light work here the proper route turns southwesterly towards the Yal de Chino, 
a tributary of the San Francisco river, a distance of forty-five miles, with a maximum grade of 
forty feet per mile. Crossing this valley to reach Pueblo creek, an ascending grade of fifty 
feet per mile for fourteen miles, thence an ascending grade of forty-five feet per mile for fifteen 
miles, enables us to make the Aztec Pass with forty feet cutting. 
The Aztec Pass divides the waters that flow into the San Francisco and Bill Williams’ fork, 
the former flowing to the Gila, and the latter to the Great Colorado. From this pass the best 
route would continue down this stream to near camp No. 108 ; thence over a small divide 
between Canon creek and White Cliff creek ; thence down the latter to its junction with Big 
Sandy, the main branch of Bill Williams’ fork. From Aztec Pass, for fifteen miles, the descend¬ 
ing grade will be sixty-five feet per mile ; thence across the Canon and White Cliff creeks 
summit, with light work, and down White Cliff creek thirty miles to the mouth of Canon creek, 
Avith a descending grade of fifty-one feet per mile, the descent, via Canon creek, from camp No. 
108 would be about seventy-five feet per mile, through a deep canon of basaltic rock. From 
the mouth of Canon creek the valley of Big Sandy and Bill Williams’ fork presents no obstacle 
that cannot easily be overcome, either in grade or curvature, to the Great Colorado. In the 
Striped canon there are several salient points which it will be necessary to tunnel to the extent 
of from one hundred and fifty to two hundred feet, in order to maintain a workable curve. 
Between camps Nos. 120 and 121 Big Sandy unites with Bill Williams’ fork, which comes 
from the northeast. From a careful examination of my topographical notes, triangulations, 
deductions, &c., I feel confident in stating my opinion as to the source of this fork—that it is 
in a pass which we saw some few miles to the south of us, between the Black mountain and 
Mount Hope. By a slight detour in the Yal de Chino, this pass can be attained, and the valley 
of Bill Williams occupied for the route there, by saving about fifty miles of distance and the 
probability of an uninterrupted descent of about twenty-eight feet per mile. 
Following up the left bank of the Great Colorado, whose ascent for thirty-four miles is about 
one and a half foot per mile, a suitable point for crossing was found among the u Needles,” a 
series of porphyritic and trap dikes, through which the stream forces a passage. Notwith¬ 
standing the formidable appearance of the rocks at a casual glance, there are but three points 
where they infringe directly upon the river, and these points are quite narrow and easily perfo¬ 
rated or blasted off entirely. To cut off a large bend of the river in the Pah-Utah valley, grades 
of about sixteen feet per mile will be necessary to pass the gravelly spurs of the plain. At the 
crossing, the rocks afford enduring abutments, and the river, being one hundred and fifty yards 
wide, easily spanned. From this point a proper location will be found, by leaving the river and 
commencing the ascent of the high table lands that lie between the Great Colorado and the 
Mohave rivers, through the pass hitherto supposed to be the embourchement of the latter, but 
which was found to be but a dry bed of a stream heading in the elevated rim of the Great Basin, 
which undoubtedly extends thus far south. Thence turning southeasterly to a junction with the 
Sierra Nevada, at the San Bernardino mountain, the exploration continued west and through a 
pass in the highest point of this river, there being much lower ground both to the north and 
south of this point, as shown by the map. This pass is attainable, however, by practicable 
grades, the maximum being about sixty-four feet per mile. 
