AN EXAMINATION 
OF THE 
REPORTS AND EXPLORATIONS FOR RAILROAD ROUTES FROM THE MISSISSIPPI TO THE PACIFIC. 
War Department, 
Office of Pacific Railroad Surveys , Washington , February 5, 1855. 
Sir : In accordance with your instructions, I submit the following result of the examination 
of the reports of the explorations, made under the orders of the War Department, to 
determine the most practicable and economical route for a railroad from the Mississippi to 
the Pacific; as well as of the explorations and surveys previously made which have a bearing 
upon this subject. 
It has been found impossible to complete the general map of the country embracing these 
and former explorations, owing to the great amount of labor required in its preparation, the 
unfinished condition of the original maps and other data upon which it is to be founded; and 
the heavy duties imposed upon the officer having it in charge. 
This map should be accompanied by a report giving the authorities and data upon which it 
rests, with explanations of the adjustment of discrepant authorities; and also a brief memoir 
upon the physical geography of the regions embraced within its limits. Such a memoir neces¬ 
sarily formed a preliminary to a report upon the most practicable and economical route for a rail¬ 
road from the Mississippi to the Pacific; but the unfinished condition of the maps and material 
collected in the departments of science necessary to elucidate the subject, and the insufficiency 
of the material, when prepared, for so comprehensive a subject, precluded the possibility of 
its being undertaken at the present time, more especially as the labors of all in the office 
were required in the preparation of the details necessary to discuss the greater or less 
degree of practicability and economy of each route separately. 
The report herewith submitted partakes more of the character of memoranda upon the differ¬ 
ent routes, than of a report upon the whole subject; and, in fact, it was prepared as such, 
with the intention, principally, of aiding your examination of the reports of the officers 
charged with the explorations, rather than as a general report upon all the routes. These 
memoranda would have served as the basis of a general report, but time does not admit of 
their being placed in that shape, and they are consequently submitted in their present condition, 
with this explanation of the cause of their deficiency in comprehensiveness of matter, and in 
arrangement. 
Upon relieving Major Emory, in August last, from the charge of the Pacific Railroad office, 
I found that the preparation of the material for the general map, a work of great labor, 
and the superintendence of its construction and drawing, had been intrusted to Lieut. G. Iv. 
Warren, topographical engineers, whose zeal and ability in the performance of this and the 
general office duty, Major Emory acknowledged in warm terms. Lieut. Warren has continued 
in charge of the office duties, which include the critical examination of the reports, maps, 
profiles, and all original data submitted by the exploring parties and others, and reports upon 
