EXPLORATIONS AND SURVEYS FOR A RAILROAD ROUTE FROM THE MISSISSIPPI RIVER TO THE PACIFIC OCEAN. 
WAR DEPARTMENT. 
EXPLANATORY NOTE. 
The reports of the Secretary of War and the revising officer, which appear in volume one, 
were founded, so far as they relate to the route near the 35th parallel, upon the preliminary 
report of Lieutenant Whipple. The following chapters, being those which are principally 
referred to in those revisory reports, are, therefore, republished. They are chapters two, three^ 
four, five, and eleven, with a portion of appendix B. The preliminary profiles are also re¬ 
printed. 
A. A. HUMPHREYS, 
Captain Topographical Engineers. 
In charge of office of Pacific R. R. Explorations and Surveys. 
Extracts from the [ preliminary ] report of Explorations for a Railioay route, near the thirty-fifth 
parallel of north latitude, from the Mississippi river to the Pacific ocean, by Lieutenant A. W. 
Whipple, Corps of Topographical Engineers. 
CHAPTER II. 
CONSIDERATIONS REGARDING THE TERMINI OP THE RAILROAD.—EXPLANATION OP THE MAPS. 
Three of the principal centres of trade upon the Mississippi river are St. Louis, Memphis, and 
Vicksburg. To these cities converge railroads, constructed or proposed, from harbors upon the 
northern lakes, from the principal ports upon the Atlantic shore, and from those upon the Gulf 
of Mexico, uniting the interests of the northern, middle, and southern States. From the above 
mentioned places railroads have been projected, and several are in process of construction, west¬ 
ward to the extreme limits of the States of Louisiana, Arkansas, and Missouri, each with a 
purpose of forming a link in the great chain of communication which must ultimately lead to 
the Pacific ocean. 
The question immediately arises, which of the various routes shall be at first prolonged ; or, 
can there be found a location for a main trunk that may be advantageously united with several 
of these branches, affording nearly equal facilities to interests so widely diffused? Nature 
seems to point out such an intermediate location near the parallel of thirty-five degrees north 
latitude, referred to in the preceeding instructions. 
Following the south bank of the Canadian river for nearly one-third of the whole distance to 
the Pacific, we pass into the valley of Rio Grande del Norte, near the centre of New Mexico, 
where the soil is the most fertile, the population is the most numerous, and the mines are the 
most productive of any part of this interior portion of our possessions. 
From Vicksburg to Shreveport the course of the railroad—already under construction—is 
nearly west. Should it be continued, as has been contemplated, to Preston, on Red river, the 
tendency will be considerably north of west. If prolonged, it would naturally ascend the fertile 
valley of the False Washita to a junction with the main branch from Fort Smith, which, in 
