COOCHETOPA PASS. 47 
often narrowed until the huge, fallen rocks from either side had passed each other and lay scat- 
tered over the bottom, the road was still good, although we had constantly to wind around these 
rocks, and to cross and re-cross the creek, here, as almost always under similar circumstances, 
with soft, springy banks. The pines are confined to the mountain tops and sides, and but few 
are of respectable size. Surrounding our camp they are small but numerous, exteuding from our 
camp-firesquite to the mountain tops. The rocks of the cliffs on all these creeks were porphyritic 
trapp and igneous rocks of various kinds. The precipitous escarpments of the narrow 1avines 
are of the former stone, very porous, and of a red cast, not unlike, but a shade lighter than the 
common red sandstone, in formations of from twenty to sixty and eighty feet in thickness. The 
crests of these bluffs are covered with earth a few feet in thickness, some terminating in larger or 
smaller plains of table-land, while others are rounded off into points and ridges. In the dry bed 
of a stream near camp we passed over a sedimentary stratum of coarse sandstone, much water- 
worn. 
September 2.— Captain Morris and myself went forward with working parties, to make practica- 
ble crossings for the wagons atthe various points where, from the winding of the streams and 
narrowness of the pass, it should be necessary, and to cut out the timber which at various points 
quite filled the pass as it covered the ridges, which at this point divide the waters of the conti- 
nent: those of the eastern slope flowing by the channels up which we have travelled for several 
days, to the Rio Grande del Norte, and thence to the Gulf of Mexico; while those from t 
western slope flow into the Rio Grande, or Grand river, one of the main branches of the Colorado 
of the West, reaching the Pacific through the Gulf of California. 
We found little difficulty on the banks of the creek, but were detained some hours by the 
dense growth of quaking-asp, from the size of saplings to a foot in diameter, among which, fallen 
in every direction, was an equally large growth of dead aspens. At11 o'clock, however, we were 
progressing rapidly towards the summit of the pass, which we soon reached, and, as We enjoyed 
the prospect before us, a slight thunder-shower was not a disagreeable accompaniment. The 
elevation of this pass is not enough to give an extensive view, but the numerous small, grassy 
valleys, and pine and aspen groves of the mountain sides to the west, afforded us a pleasant pros- 
pect, the more so as it gave hope of an easy prosecution of our future labors, at least for a time. 
After cutting away trees for a quarter of a mile down the western slope, we entered an open 
prairie, at a spring which sends out a fine little creek, which we followed for a mile, without 
obstruction, and encamped, at half-past 1 o'clock p. m., in a fine field of grass, where two or 
three mountain rills, coming from as many small valleys, unite. Distance, five miles and a quar- 
ter. Latitude, by observation, 38° 12’ 35”. 
The width of this pass at the summit does not exceed six hundred yards, but the slopes to the 
low peaks rising above it are not abrupt. The ascent from the valley of San Luis, by which 
we reached the summit, was very gradual, increasing with considerable uniformity until we ap- 
proached it within a short distance, where the ravine of the stream was narrow and thickly tim- 
bered ; and we left it with the wagons, making an abrupt ascent to the right to the level of the 
summit, “ which we could have reached by an easier grade," Captain Gunnison says in his sapien 
“by keeping to the left of our track, where the ravine winds gently round to the summit-level. 
The approximate elevation above the sea of our camp at the Puerta, as we left the valley of 
San Luis, was 7,567 feet. To our next camp, twelve miles and twenty-seven hundredths above 
the Puerta, on the Sahwatch cree k, we ascended slightly over thirty-nine feet to the mile; and in 
the next fifteen miles, to our camp 3.83 miles east of the summit, we ascended 913 feet, or nearly 
sixty-one feet to the mile; our altitude at this camp being 8,960 feet, while the indicated height 
of the summit itself is 10,032 feet, giving an ascent of 279 fcet 9 inches per mile for 3.83 miles; 
and of our camp on Pass creek, one mile and thirty-three hundredths west of the summit, 9,540 
feet—a descent of 492 feet in that distance, or, whole numbers, 370 feet per mile. 
Captain Gunnison describes the system of barometric levelling which he employed on several 
