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APPENDIX A.—PROGRESS OF THE SURVEY. 
My exploration on the west side of the Kansas was eminently successful, in developing the 
existence of a plain, slightly inclined, which cuts off the eastern bend of that river at the Smoky 
Hill. Thence I came, in the same course, to Walnut creek, and descended to its lower part, 
and afterwards reconnoitred above. The result would be that a road should take this more 
direct line from Fort Riley to Walnut creek, and cross to Pawnee fork, following it and branches to 
within five or six miles of the Arkansas; thus cutting off the “Big Bend,” and strike the latter 
river near “Aubrey’s crossing.” I beg leave to refer to Captain (Lieutenant) Woodruff’s map 
of the Pawnee fork in explanation—a manuscript copy of which I saw at Fort Atkinson. 
Those in my command who had been in this country in winter, could not recognise places and 
streams in a different season. Misled by the maps of the Upper Arkansas, I took the Apishpa 
for the Huerfano, and thoroughly explored the country below, and have added to the geography 
of that region at the expense of much personal labor. 
An intelligent man, of thirty years’ mountain experience, was procured.at the Greenhorn ranch, 
for a guide to the “Sangre de Cristo” Pass. By a circuitous route we were led to the mule- 
path crossing over a high mountain or ridge, which the guide declared the only way. But I 
reconnoitred the dividing ridge from near the Sierra Blanca to the Spanish peaks, while the train 
was cutting through bushes and working a road, under my able assistant officer, down the 
Sangre de Cristo creek to this valley. 
My efforts were rewarded by finding a summit level, very low, and over which a road can 
easily be made, with almost a single grade of a few feet to the mile, to the Arkansas plains. 
As an obstacle to a railroad, it deserves not the name; and the pass can be made without going 
up what could be called a hill—a mere slope. The work bestowed on the Muleteer mountain 
track would have opened a feasible road for supplies to this post from the States, and, perhaps, 
ultimately the route to Santa Fe. 
There is a good wagon-track now made, where we have come with heavily loaded teams. 
A large flock and herd are closely following us. The owner has been to one of my camps, and 
returned to the Arkansas to bring on his stock, as the grass is extremely good, and this route will 
not require wintering in the Basin. 
My observations on the east side lead me to think there is a pass to the north, more direct and 
as feasible, which I shall soon examine. 
We are to start early to-morrow morning for the north and Coochetopa. I have secured the 
services of A. Leroux to the Spanish trail, whence he will return to guide Lieutenant Whipple. 
All accounts agree in presenting greater difficulties ahead; but I hope to report in a few weeks 
from the Great Basin. 
Great press of business, and a severe headache, must plead my apology for the style of this 
letter. 
I have the honor to be, your most obedient servant, 
J. W. GUNNISON, 
Captain Top. Engs., Commanding Central Pacific Railroad Survey. 
Hon. Jefferson Davis, Secretary of War. 
III.— Letter dated August 22, 1853, Camp, Utah Creek, near Fort Massachusetts, from Captain 
Gunnison to Colonel J. J. Abert, reporting the progress of the survey. 
Camp, Utah Creek, near Fort Massachusetts, 
August 22, 1853. 
Sir: I have honor to report my arrival in the San Luis valley, having crossed the Rocky 
mountain eastern range without accident. We have had much labor in removing trees and 
bushes, and cutting down banks, to work up the east side of a high ridge, over which my guide 
