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LIST OF MAPS ACCOMPANYING REPORT. 157 
36. Report of the meteorology of the route, by Lieut. C. Grover, U.S. A., from Fort Benton to 
Wallah-Wallah. 
37. Report of Mr. Tinkham of the snows of the Rocky mountains in November, of the Bitter 
Root in December, and of the Cascades in January, 1853. 
38. Letter of the Hon. H. M. Rice, and extracts from letters from Hon. H. H. Sibley and A. Cul- 
bertson, Esq., as to the winter climate of the region extending from the Mississippi river to 
the base of the mountains. 
For much additional information in regard to snows, see the several reports of Lieut. Mullan. 
dis 
39. Report of Mr. George Gibbs to Capt. McClellan on the Indian tribes of the Territory of 
Washington. 
40. Report of Lieutenant John Mullan, U. 8. A., on the Indian tribes in the eastern portion of 
Washington Territory. 
41. Reports of Mr. James Doty on the Indian tribes of the Blackfoot nation. 
42. Report of Mr. J. M. Stanley’s visit to the Piegan camp at the Cypress mountain. 
Inpran AFFAIRS. 
The following maps accompany this report : 
1. General map: scale, ¢ya0000 3; Showing the connexion between the route explored and exist- 
ing roads, and the routes still requiring examination to determine the best route, and its con- 
nexions with the routes to the south, with a comparison of the profiles of the route by the 
northern passes, and of the South Pass, by Mr. John Lambert, topographer. 
2. General sketch of the routes explored: scale, tz>00003 three sheets, by Mr. John Lambert, 
topographer of the expedition. 
3. Map of the Cascades: scale, gotoo00 3 by Lieutenant J. K. Duncan, U. S. A., under the orders 
of Captain George B. McClellan, corps of Engineers. 
4, Map showing the several barometric profiles, with comparisons of such as come into com- 
petition. 
5. Sketch of the tunnels required on the several lines. 
The result, therefore, of the year’s exploration, has been to establish the practicability of the 
northern route ; but it is not believed that the best route has been ascertained; and it is known 
that only the materials have been collected of a very general estimate of the cost of the road. 
An approximate estimate can be made by throwing the whole distance into parts, having a com- 
mon character, referring them to similar roads in the States of which the cost is known; and 
thereby, by making a proper allowance for the changes of circumstances, as the increased price 
of labor, and the expense incident to operating on a long line, and in a new country, arrive at the 
cost of the road. 
It is important, however, that the field should be extended to embrace all probable routes, that 
the best route should then be selected, and that detailed instrumental surveys be made, to ascer- 
tain the cost and determine the best plan of construction. 
The greatest western development of roads is now in Missouri and Iowa, two roads being 
under construction in the former, and one in the latter State, extending to their western bounda- 
ries; and an additional road being projected, and soon to be placed under construction in Iowa, 
from Rock Island to Council Bluffs, and connecting with the road on which the cars now run 
from Chicago to Rock Island. 
Roads are also extending from Chicago and Milwaukie to points on the Mississippi, from Rock 
Island to St. Paul, and to the Fond du Lac of Lake Superior and Green Bay. 
An examination of the maps will show that, if the Black Hills are practicable for roads, the 
Hell Gate passes are in most admirable connexion both with the roads of Missouri and Iowa, 
say at Council Bluffs, and with the roads from the Great Lakes, moving through Minnesota and 
centering in the grand plateau of the Bois des Sioux. 
