GENERAL ORGANIZATION OF THE EXPEDITION. 3 
with the measurements by the odometer, will be obtained. In the crossing of rivers, the height 
of the banks must be noted; the depth of the water, the apparent highest water, the nature of 
the bottom on which the foundation for the abutments and piers must rest, the width between 
the banks, and all information determining the means and cost for carrying a road over the 
stream, should be obtained as fully as practicable. So, in smaller crossings of gullies and small 
streams, similar facts in reference to culverts should be obtained. In general, everything in 
the character of the country passed over affecting the construction of a railroad will be noted, 
the estimated or determined grades, the nature of the excavation, facilities for obtaining stone, 
timber, and all building materials, &c., &ec. 
The positions of all objects noted on the route will be determined either directly by the 
odometer and compass, referred to the line of the route by compass bearing and estimated dis- 
tance from one point, or simply sketched in, according to the importance of the object. 
3. The decisive points which must determine the location of the road are the mountain 
passes of the Cascade and Rocky mountain ranges; and it may occur that the location of the 
road between the two ranges, and for a long distance east of the Rocky mountains, must be sus- 
pended until these passes be examined and selected; and much of the general reconnaissance 
must be made after the selection of these mountain passes, which are the controlling points of 
the survey. 
It is proposed to construct the following maps, embodying the geographical results of the 
exploration ; and the efforts of reconnoitring and surveying parties will be especially directed 
to obtaining the best data for the construction of these maps: 
A general map, scale 3354553, from the headwaters of the Mississippi river to the Pacific 
ocean, and from the 42d to the 56th parallel. 
A map in two sheets, scale ;z54y55, of Washington Territory, and thence eastward to the 
headwaters of the Mississippi. 
A map, scale z5 557, Cascade range, Rocky mountains, and other critical points of the route. 
Mountain passes, scale gyhyy- 
Working sketches, scale z545,-. 
The field-books are constructed so as to be convenient for reduction to the scale of the several 
maps above. As ruled, in small squares of about 3 inch side, each side represents } of a statute 
mile, scale z5455, and it is designed that this scale should be generally used in sketching. 
Where necessary, however, to depart from it, the sketches should be of a scale sj55, gotu0> 
suiss, &e., the sides of the squares respectively representing 3!5, +!5, 4, statute mile, as shall be 
found necessary, the scale by which the sketch is made being marked on the page containing it. 
The direction of the magnetic meridian of the sketch (running longitudinally down the page, 
or taking the direction of the other sides of the square, as shall be most convenient at different 
times) will also be noted on each page, and the magnetic variations recorded in the field-book 
with each day’s work. 
The work of the day will be made up in camp at night with ink, and will be transferred by 
the draughtsman to the general map, scale ;zy2s00- 
GENERAL ORGANIZATION OF THE EXPEDITION. 
1. The expedition is in charge of Isaac I. Stevens, governor of the Territory of Washington. 
2. There will be two main parties in prosecuting the work. One party, under the immediate 
direction of Governor Stevens, will proceed from the Mississippi river, and surveying rapidly 
the intermediate country, will reach as early as practicable the Rocky mountains, and examine 
all the passes to ascertain the most practicable one. The second party, under the command of 
Brevet Captain George B. McClellan, will organize at Puget sound, or on the Columbia, and 
operate for a similar purpose in the Cascade range of mountains. The partie: °°’ operate in 
