THE LINE UNWORTHY OF FURTHER EXPLORATIONS. 87 
be overcome by from 175 to 200 feet, and giving a grade of 131 feet per mile for 3.6 miles west 
of the summit, and thence to the vicinity of our camp of September 13, or even less than this, 
by keeping on the side of the ravine above Salt creek. Altitude of the pass, 7,820 feet. 
Two miles from this point, towards the valley of the Sevier river, Salt creek, (by following 
which a railroad can alone be carried), enters a rocky cafion, more or less broken by lateral 
streams, which it follows for sixteen miles. ‘Through this canon a railroad may be carried, 
but, owing to rock cutting, only at a very heavy expense." The altitude of our camp, two 
miles above its head, on Salt creek, was 6,976 feet, to which seventy-five feet must be added, 
to connect with the estimated grade for a road at that point, which will give a descent of 
ninety-five feet per mile for the eighteen miles intervening between that point and the foot of 
the cañon, 1,706 feet below it. For 2.65 miles below the cañon, to the foot of the mountains, 
we descended 91 feet per mile; and from the foot of the mountain to our first camp on the 
Sevier river, 3.13 miles, the descent was 27 feet to the mile. 
No other than the most ordinary obstructions exist to the construction of a railroad from this 
camp to the most western point of our explorations, near the Sevier lake. It should follow the 
river, passing with it through its gorge in the Un-kuk-oo-ap mountains; and thence take its 
course to the west. The average fall of the river for thirty-one miles, upon which observations 
were taken for three days, is but four feet to the mile; and it continues this easy descent to the 
lake. 
For crossing the four main streams upon this line, heavy and expensive bridges will be re- 
quired ; especially those over Grand, Blue, and Green rivers, whose currents are very powerful 
and rapid, and annually subject to enormous freshets—the Arkansas being, comparatively, a 
gentle stream. And, besides these, after approaching Grand river, the ordinary side ravines and 
cañones requiring bridges are very numerous, while the passage of each of the more formidable 
ones can only be accomplished by great labor and at an enormous expense, to say nothing of 
their aggregate cost. 
If more minute surveys shall at any time be made upon this general line, alterations and im- 
provements will doubtless be made in it to some extent, but its general character cannot be im- 
proved. A pass may be found, as suggested, at the head of the Coochetopa creek, in the Sierra 
San Juan, which may be superior to the Coochetopa Pass itself, and a more direct line from Green 
river to the Wahsatch Pass be secured, by following the Spanish trail across the Rock Hills, or 
even by ascending the San Rafael river, but, if found more favorable or direct, will not alter the 
general character of the route; for the line followed is not only the best that could be discovered 
in the vicinity, but was pointed out to us, as such, by the most reliable and experienced guides 
we could obtain, and who had recommended the route as very superior, and may reasonably 
be supposed to have done all they could to establish the correctness of their judgment, and by 
the Indians who inhabit the country, and are as familiar with every fastness and mountain pass 
in it as with the use of the arms with which they procure their daily subsistence. 
And after the most careful observation and study I have been able to bestow upon the various 
chains of mountains and water-courses upon the route, seen at least during parts of every day, in 
the clear atmosphere of the elevated mountain regions, with a distinctness of outline and clear- 
ness of detail at distances difficult to be realized by persons who are only familiar with the 
extent, beauty, and grandeur of landscape views in the comparatively moist and clouded atmo- 
sphere of the more civilized portions of our country, I hazard nothing in saying that no other line 
exists, in the immediate vicinity of this, worthy of any attention in connexion with the construc- 
tion of a railroad from the Mississippi river to the Great Basin. 
For the geographical positions (latitudes) laid down from astronomical observations in this 
report and accompanying map, I am entirely indebted to my accomplished assistant, Mr. S. 
Homans, astronomer for the expedition, by whom the observations were taken and the compu- 
tations made. Our entire failure to obtain suitable observations for longitudes, is explained in 
