The warning in the last paragraph seems almost prophetic; for, as will be seen hereafter, McClellan’s fear of deep snows caused him to fail in an important part of his survey of the Cascade passes, viz., the determining the depth of winter snow.
Governor Stevens also obtained the detail for his survey of Lieutenant A.J. Donelson, of the engineer corps, and ten non-commissioned officers and men, of the engineer company, also known as sappers and miners, and of Lieutenant Beekman Du Barry, of the 3d artillery. He also obtained from the War Department authority to call upon the several army administrative departments for transportation, subsistence, and arms, and even the pay of two civilian surgeons and naturalists, thus providing for all the expenses of the expedition except those pertaining to civilians employed as a scientific corps and their assistants, which were to be defrayed by the funds allotted to the Northern route out of the civil appropriation, viz., $40,000 out of the $150,000 thus appropriated. By these arrangements he vastly increased the extent, thoroughness, and value of his exploration.
On April 7 Governor Stevens sent Lieutenant Donelson to Montreal armed with letters from the British Minister in Washington to Sir George Simpson, governor of the Hudson Bay Company, to obtain all the information possible relative to the country from the Great Lakes to the Pacific, the location of the trading-posts, the amount of supplies obtainable from them for the exploration party in case of emergency, the names of hunters and half-breeds who might serve as guides and interpreters, and to learn all possible about the geography, and examine all books and maps, making copies of the latter if necessary, etc.
“The information we already have of this region,” he writes Donelson, “is based upon the following works: Lewis and Clarke’s Travels; Irving’s Astoria and Rocky Mountains; Travels by the Missionary De Smet, Nicollet, and Pope; Governor Simpson’s Journey around the World; and some information, not yet published, obtained from Dr. Evans on his geological survey of those regions. A book recommended by the British Minister, ‘Hudson Bay Company,’ by Montgomery Martin, I wish you to obtain. He suggested it might be obtained from Governor Simpson. As soon as you have finished your inquiries at Montreal, which I think you can do in a week, return to Washington, and report to me in person.
“In reference to the detachment (sappers), it is necessary that the men be selected with great care. None should be taken who cannot assist the scientific corps as sketchers, draughtsmen, or collectors, etc. It is necessary that they should be put under special training. Captain Seymour, perhaps, might be willing to take charge of one, and Lieutenant Du Barry of another, giving them instructions in the use of the barometer and astronomical instruments used in the field.”
This is interesting as showing how little was then known of the region to be explored, and how few and meagre were the works describing it.
Governor Stevens had thus been driving the work of preparation and organization for a fortnight, when, on April 8, the formal order placing him in charge and giving full instructions was issued by the War Department. These instructions exactly embody his own suggestions, much of them in the very language of his letters and memoir to Secretary Davis. In fact, he really prepared his own instructions. The following brief synopsis will give some idea of the scope and magnitude of the exploration, of the task Governor Stevens had set himself:—
1. The exploration and survey of a route for a railroad from the sources of the Mississippi River to Puget Sound is placed in charge of Isaac I. Stevens, governor of the Territory of Washington, to whom all officers detailed for the same will report for instructions.
2. To operate from St. Paul, or some eligible point on the Upper Mississippi, towards the great bend of the Missouri River, and thence on the table-land between the tributaries of the Missouri and the Saskatchewan to some eligible pass in the Rocky Mountains. A depot to be established at Fort Union, at the mouth of the Yellowstone, with a subsidiary party to await the coming of the main party. A second party to proceed to Puget Sound and explore the passes of the Cascade Range, meeting the eastern party between that range and the Rocky Mountains, as may be arranged by Governor Stevens.
3. To explore the passes of the Cascade Range and Rocky Mountains from the 49th parallel to the headwaters of the Missouri River, and to determine the capacity of the adjacent country to supply, and of the Columbia and Missouri rivers and their tributaries to transport, materials for the construction of the road, great attention to be given geography and meteorology of the whole intermediate region, to the seasons and character of freshets; the quantities and continuance of its rains and snows, especially in the mountain ranges; to its geology; in arid regions the use of artesian wells; its botany, natural history, agricultural and mineral resources; the location, numbers, history, traditions, and customs of its Indian tribes; and such other facts as shall tend to develop the character of that portion of our national domain, and supply all the facts that enter into the solution of the particular problem of a railroad.