GENERAL ORGANIZATION OF THE EXPEDITION. 3 



with the measurements hy 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., &c. 



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 34^^75-, 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 75^77^5 of Washington Territory, and thence eastward to the 

 headwaters of the Mississippi. 



A map, scale ^^7^) Cascade range, Rocky mountains, and other critical points of the route. 



Mountain passes, scale 



Working sketches, scale 



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 inch side, each side represents ^ of a statute 

 mile, scale TulirTrj an( ^ ^ * s designed that this scale should be generally used in sketching. 

 Where necessary, however, to depart from it, the sketches should be of a scale S^TF? TTTTfTnr&amp;gt; 

 strtWirj &c., the sides of the squares respectively representing ^j, T ^, ~, 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 



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 parties will operate in 



