INTRODUCTION. 
GENERAL SKETCH OF LINES EXPLORED. 
Shortly before the close of the session of Congress in March, 1853, an appropriation of 
$150,000 was made to defray the expenses of the survey of the various routes along which it 
was supposed that a railroad might be constructed from the Mississippi river to the Pacific 
ocean. For this purpose six parties were organized by the War Department for the survey of 
four main routes ; and ina short space of time they were in the field. All the parties were 
fitted out in the most complete manner ; the natura] history apparatus and material prepared 
under the direction of the Smithsonian Institution, which also furnished the necessary instruc- 
tions as to the objects most important to be collected. In its efforts to secure the assignment 
to these parties of persons capable of making collections and observations in natural history, it 
was met by the hearty co-operation of the War Department, through the heads of the different 
expeditions, and Captain Humphreys, in charge of the Pacific Railroad Office. 
It is, of course, not necessary in this place to give an account of the personnel of these parties, 
nor any detailed history of their routes or results; but, as explaining the origin and objects of 
the present report, a brief sketch of each, with a statement of the naturalists accompanying 
them, will be required. The parties organized in 1853 were as follows : 
1. Line oF THE 47TH PARALLEL, UNDER Governor I. I. Stnvens.—This portion of the survey, 
placed undér the command of Governor I. I. Stevens, was most extensive in its organization, 
and first in the field. It was divided into two quite distinct parties, one proceeding across the 
country to the Pacific, the other starting at the Columbia river and moving towards the east. 
The first division, immediately in charge of Governor Stevens, left St. Paul (where it was 
principally fitted out) on the 8th of June, 1853, and proceeded directly to Fort Union, at the 
mouth of the Yellowstone. Here it was joined by Lieutenant Donelson, who had embarked in 
the Fur Company’s boat at St. Louis. From Fort Union the party proceeded along the Missouri 
to the mouth of Milk river, and up this stream to Fort Benton; thence across the mountains to 
the Mission of St. Mary’s; thence to Fort Colville, by the way of the Coeur d’ Alene; and finally 
to Vancouver and Olympia. Collateral lines were also traversed at the same or different times 
by Lieutenant Mullan, Lieutenant Donelson, Lieutenant Saxton, and others. 
The western division of the line, under command of Captain G. B. McClellan, proceeded 
from New York to San Francisco ; thence to Vancouver, and next explored both sides of the 
Cascade mountains for some distance northward. The party met Governor Stevens at Fort 
Colville, and continued thence to the northern boundary line. 
The main party, under Governor Stevens, was accompanied by Doctor George Suckley, 
United States army, as surgeon and naturalist, although collections were also made by Lieu- 
tenants Donelson and Mullan. Doctor Suckley’s chief points in collecting were St. Paul’s, Bois 
