RAILROAD SUMMARY OF THE ROUTE. 83 
upon the line: on the Wahkarrussi, an affluent of Kansas river; on Grand river, at Salt and Bit- 
ter creeks; and near our camp of the 11th of October, on Big Rock creek, at the eastern base 
of the Wahsatch mountains. "That on the Wahkarrussi has been more or less used, and is doubt- 
less abundant and good; and if the supply should not prove abundant upon working the other 
localities observed, the formation is such, at least on Grand river, as to render it highly probable 
that an inexhaustible supply of coal exists in the immediate vicinity. 
The great scarcity and unequal distribution of timber upon this line renders the character of 
its rocks an important subject of inquiry. The great body of those underlying the Plains are sand- 
stone, more or less argillaceous, the strength and durability of which in superstructures can only 
be estimated from their appearance, the soil formed from their disintegrations, and the apparent 
rapid decay of most of the ledges exposed to the weather, which indicate inferior stones. Captain 
Gunnison says that the barracks at Fort Riley are being built of the white limestone of the 
vicinity; and a superior quality of limestone is found on the Arkansas, below Bent’s Fort, and 
various localities of it are indicated in Dr. Schiel's geological report, appended to my report of 
subsequent explorations. 
A more minute and extensive examination of the Plains would probably discover the existence 
of limestone and other rocks in various localities; but as no heavy masonry will be required in 
carrying a road over the Plains, in the absence of other rocks those already known will be 
sufficient. At the Huerfano butte, where they exist in abundance for building purposes, the first 
granitic rocks were seen. Thence westward to Sevier lake, soft disintegrating sandstones 
underlie the plains, and form many of the lower mountain ranges and hills, but the higher ranges 
of mountains will furnish superior qualities of stones for railroad structures. On Grand river, 
granite forms the head of the first cañon, overlaid by sandstone, with a thin stratum of igneous 
rock capping the high tables. Granite is also found in the Sangre de Cristo Pass and at Sahwatch 
butte. In the Sangre de Cristo Pass, the gray rocks have a crystalline porphyritie structure ; in 
the approach to the Coochetopa Pass, they are red and more vesicular; and in the Wahsatch 
Pass, approach the basaltic character. 
From the vicinity of the mouth of the Kansas river to the foot of El Sangre de Cristo Pass, 
in the eastern range of the Rocky mountains, the features of the country are very favorable 
for the construction of a railroad. By the line we followed, it is generally an open rollin 
prairie to where we crossed the Arkansas river, with a very gradual but uniformly increasing 
elevation to the west. West from the mouth of the Apishpa, on the north side of the Arkansas, 
the prairie hills begin to rise abruptly, and extend closer in to the river; but on the south side 
rise more gradually, sweeping up in gentle swells to the divide between the small ravines which 
descend to the Apishpa on the south, and the Arkansas and Huerfano rivers on the north. Pre- 
serving the elevation thus gained, the line is easily extended west to the Cuchara and Huerfano 
rivers above their cañones; entering the valley of the latter stream a few miles below its butte, 
and ascending it to our camp of August 9th, which may be regarded as the foot of the Sangre 
de Cristo Pass, whose summit is, by our trail, fourteen miles above this point. In constructing a 
railroad across the Plains to the foot of this pass, the only obstacle to be overcome not encoun- 
tered by similar constructions in all open, rolling prairie countries, is in the gradual western ascent 
frorn the Mississippi river to the foot of the Rocky mountains; and this ascent, as has been already 
stated, by ascending the main water-courses, (the Kansas and Arkansas rivers and their tributa- 
ries,) is very gradual, increasing with a general uniformity as we approach the mountains. 
The elevation of our camp near Westport,on the western border of the State of Missouri, was 
990 feet above the Gulf of Mexico, and 615 above low-water mark at St. Louis. On Pawnee 
fork, an affluent of the Arkansas, 293 miles by the Santa Fé road, and 322 miles by the Smoky 
Hill route, from that camp, our elevation was 1,962 feet above the Gulf; giving an average ascent 
per mile (independent of the ordinary inequalities of the ground, which were noted from day 
to day) of three feet three inches, and three feet, respectively. By the path which we followed, 
