82 EXTENT OF EXPLORATIONS.—SALUBRITY OF THE REGION, 
The results thus far accomplished may be summed up as follows: The Missouri and Columbia 
rivers, with the exception of sixty miles of the latter, have been surveyed; three passes, including 
that of the Columbia river, have been explored in the Cascade and Coeur d’Alene mountains ; 
nine passes in the Rocky mountains ; two lines have been run from the Mississippi river to the 
base of the mountains; ranges of country south of Fort Union, and between the Yellowstone 
and Missouri rivers, at the eastern and western bases of the Rocky mountains from above our 
parallel to the forks of the Missouri, and in the Territory of Washington, between the Cascade 
and Cceur d’Alene mountains, have been explored. Not only has information been collected in 
reference to the routes for a railroad, but attentive consideration has been given to wagon 
roads, to the navigability of the rivers and the part they must play in establishing communica- 
tions, the adaptation of the country to settlement, the Indian tribes, and the military posts that 
ought to be established. Additional explorations and surveys ought, however, to be made, to 
determine the most practicable route for the road, and, incidentally, still further to develop the 
geography and resources of this region of country. Before passing, however, to the consideration 
of these questions, [I will advert to the remarkable salubrity of the whole region included in the 
exploration. 
The reports of medical officers, Dr. Suckley and Dr. Cooper, will show the healthiness of 
this route. From the Mississippi to Fort Union, in a force of eighty-six men, there were slight 
ailments growing out of too free use of buffalo meat, and the use of saline water, good camping 
grounds not having been selected; but they yielded readily to treatment, only one person having 
been confined to his bed, and that was in consequence of his own gross imprudence. With 
proper choice of camping grounds, there will be no difficulty in nearly always procuring good 
water, and plenty of it. 
This portion of the route was made from June 10th to August 1st. From Fort Union to 
Fort Benton, the party consisted of over one hundred persons, and the time occupied in the 
march was from August Sth to September 6th—distance 375 miles. Three men became sick, 
but in each case it was the breaking out cf chronic complaints of long standing. From Fort 
Benton to the Great Plains of the Columbia, the route passed through a well-wooded and bounti- 
fully watered country, and there were no cases of sickness in the command. 
There was, in the remaining portion of the journey, but one slight ailment; though on 
approaching the lower Columbia, and in the journey from Columbia barracks to Olympia, the 
command was exposed to frequent rains. I do not include the case of two persons whose indis- 
position was caused by gross negligence, and which is referred to in Dr, Suckley’s report. The 
Indians on the route were free from epidemic diseases. 
The health of the party engaged in the exploration of the Cascades was also exceedingly good. 
No epidemic diseases prevailed. Disorders of the digestive organs were common, but yielded 
readily to treatment. The great dryness of the climate, and the perfect drainage of the country, 
prevent the prevalence of malarious diseases. Whole tribes of the Indians have, however, 
been almost exterminated by the small-pox. The Indians never suffer from diseases of the 
digestive organs, though dry fish and berries are their invariable food. ‘They have sore eyes, in 
consequence of the smoke of their badly ventilated huts, and consumption is common among them, 
in consequence of poor clothing and shelter, combined with the use of a scanty and innutritious 
quality of food. On reviewing the whole route, the unequalled and unparalleled good health of 
the several parties operating over an extent of country eighteen hundred miles in length appears 
remarkable, especially when we consider the hardships and exposure necessarily incident to such 
operations. Not a case of fever or ague occurred. Such a state of health can only be accounted ~ 
for by the great salubrity of the country explored, and its freedom from malarious or other 
epidemic diseases. 
