60 ROUTE NEAR THE FORTY-FIRST AND FORTY-SECOND PARALLELS. 
There is no drainage from this plain, the waters of a few small streams and springs forming 
grassy ponds upon itssurface. In its general features it is similar to the Great Basin, excepting 
that as more rain falls upon it, the vegetation is comparatively luxuriant. 
The two routes by which this plain is reached from the Great Basin, and the descent after- 
wards made to the Sacramento river, are described in detail in the concluding chapter of Lieu- 
tenant Beckwith’s report. 
That called the Madelin Pass, the more northern, is most probably the better of the two, and 
is the only one necessary to be considered. Leaving Mud lake, it ascends by the valley of 
Smoky creek, for three miles through a narrow gorge (from 100 to 150 yards wide) in an 
outlying spur of the Sierra Nevada. The sides, formed of coarse, crumbling, metamorphic rock, 
much broken by side ravines, rise abruptly to the height of from fifty to two hundred feet on 
the south, and toa much greater elevation on the north side. The course of the gorge is 
direct, and can be followed without difficulty by a railroad. Above the gorge, the valley 
expands to the width of half a mile and a mile, and again becomes narrow; being enclosed on 
the north by retreating mountain spurs, the means of ascending by a very uniform grade is 
afforded. Near the summit the grassy ascent is but 200 yards wide, with rocky hills rising 
gently two or three hundred feet above it. The pass is, thus far, of a very favorable character; 
the length of the ascent is 22.89 miles, the difference of elevation 1,172 feet, the altitude of the 
summit 5,667 feet, and the steepest slope 75 feet per mile. 
By a gentle descent for five miles the plateau is gained, and then crossed to the low ridge 
enclosing it to the west, the summit elevation of which, 5,736 feet, is attained by following 
a ravine valley, sometimes a mile, at others a quarter of a mile wide, bounded by ridges 
rising gently on either side. The descent is commenced by a narrow ravine, and is at first 
rapid, 420 feet in 2.4 miles; but the ravine soon widens, and a creek descends from it with 
a free current, a tributary of the Sacramento river. A cut is proposed at the summit 120 feet 
deep, running out to the surface at either end, making a length in all of four miles, and a 
grade of 124 feet per mile for 2.4 miles. It may be preferable to tunnel instead of cutting, 
or to cut only one-half the depth proposed. 
The open plain of Round valley, on the Sacramento, is reached 15 miles from the summit, 
(difference of elevation 1,300 feet,) over one-half of which distance the road must be located 
along the mountain on the northeast side of the stream. Although the greater number of 
ravines is found on that side, there are no cafion walls, two of which exist on the southwestern 
side, 
From this point the route lies over the smooth plain of Round valley to the head of the 
first caiion on the Sacramento, a distance of 15 miles. 
This cafion is a formidable obstacle to be overcome. Its entire length is nearly 14 miles, 
succeeded by an open valley of similar extent, which is followed by a second cafion nine miles 
in length, of the same character as the first. From the mouth of Canoe creek, four miles below 
the foot of the second cation, for the space of 96 miles the course of the Sacramento lies entirely 
through heavily timbered mountains, which rise precipitously from the river-banks to the 
height of from 1,500 to 2,000 feet above the stream. Its course is very sinuous, with all 
varieties of curves greater than a right-angle, and is seldom entirely straight for two miles 
consecutively. The construction of this portion of the route, 136 miles in length, would be 
one of no ordinary difficulty or expense under the most favorable circumstances of dense 
population, and the facilities of railroad construction which it would afford. It is impossible, 
with the data presented, to form a reliable opinion of its probable cost. To set down the 
amount of labor required at that of the Hudson river railroad, will be, it appears to me, to 
under-estimate it, since only a portion of that railroad, 144 miles long, runs through the mount- 
ainous district, whereas the whole of this is of that character. 
As an intelligible description of these portions of the river cannot be more brief than that 
of Lieut. Beckwith, I make the following extract from his resumé of the route: 
