CHAPTER XVIII. 
Papers annexed to the Report.—Maps accompanying the Report.—Field remaining to he 
Explored .— Concluding Observations. 
The following papers are annexed to, and form a portion of, the report: 
A. —General Reports. 
1. Report on the topography of the route from the Mississippi river to the Columbia, by Mr. John 
Lambert, topographer of the exploration. 
2. Preliminary notice of the geology of the country explored, by Dr. John Evans, geologist. 
3. Medical reports of Dr. George Suckley, assistant surgeon U. S. A., and Dr. J. G. Cooper, 
surgeon of the expedition. 
B.—Survey of the Cascades. 
4. Railroad practicability of the Cascades, and of the line of the Snoqualme Pass, by Captain 
George B. McClellan, corps of Engineers, United States army, in command of the western 
division. The survey of the Snoqualme Pass was carried by Captain McClellan up the 
valley of the Yakima to three miles west of the dividing ridge. 
5. Railroad report of the practicability of the Snoqualme Pass, and the obstructions to be 
apprehended from snow, by Mr. A. W. Tinkham. Mr. Tinkham extended the survey 
from the point to which it had been carried by Captain McClellan, to Seattle, on Puget 
sound, and made examinations of the depth of snow in the month of January, 1854. 
6. Report of Mr. F. W. Lander, civil engineer, on the railroad practicability of the pass of the 
Columbia river. 
C.—General Reports of the Survey of the Cascades. 
7. General report of Captain George B. McClellan, corps of Engineers, U. S. A., in command 
of the western division. 
8. Topographical report of Lieutenant J. K. Duncan, U. S. A., topographer of the western 
division. 
9. Natural history report of Dr. J. G. Cooper, naturalist of the western division. 
D. —Surveys from the Mississippi to the Base of the Mountains. 
10. Report of the Dead Colt Hillock line, by Lieutenant C. Grover, U. S. A. 
11. Report of Mr. F. W. Lander, assistant engineer, of the crossings of the Mississippi. 
12. Report of Mr. A. W. Tinkham, assistant engineer, of his reconnaissance of the “Three 
Buttes,” and of his reconnaissance on the route. 
13. Report of Dr. John Evans, of his route south of the Missouri and Yellowstone, and between 
the Milk and Missouri rivers. 
E. —Navigability of the Missouri. 
14. Report of Lieutenant A. J. Donelson, corps of Engineers, United States army, of his survey 
ol the Missouri to Fort Union, and of his reconnaissance of the country in the vicinity of 
Fort Union between the White Earth and Big Muddy rivers. 
