90 EXPLORATIONS FROM A. D. 1852 TO A. D. 1857. 
RECONNAISSANCE FROM FORT RIDGELY TO FORT PIERRE, BY CAPTAIN A. SULLY, SECOND INFANTRY, 
“ IN 1856. 
A reconnaissance was made of this route by Captain Sully, whose company formed part of 
the command of Lieutenant Colonel Abercrombie, in making the movement between these two 
posts. Topographical sketches were made with a pocket compass and estimated distances. 
Captain Sully determined the source of the Big Sioux river to be in Lake Kampeska. This 
map and the report are not yet published. 
RECONNAISSANCE ON THE MISSOURI AND YELLOWSTONE RIVERS, BY LIEUTENANT G. K. WARREN, TOPO- 
GRAPHICAL ENGINEERS, IN 1856. 
A map on a scale of 1 to 600,000 has been prepared and the material reduced from it to the 
Pacific railroad map. The detailed report and map are not yet published. 
On this reconnaissance I was assisted by Mr. N. H. Hutton and Mr. J. H. Snowden, assistant 
topographers, Drf and F. V. Hayden, geologist and naturalist, and was provided with an astrono- 
mical transit, a sextant, chronometers, barometers, odometers, and compasses. We started on a 
steamboat from St. Louis, April 16, to join General Harney at Fort Pierre, and on our way made a 
map of the Missouri from the mouth of the Big Nemeha. At Fort Pierre I received orders from 
General Harney to proceed on board the American Fur Company's boat St. Mary, and examine 
the Missouri river as far as she should go, and then to return down the stream by Mackinac 
boats. The Missouri river was thus mapped as far up as the mouth of the Big Muddy, sixty 
miles above Fort Union. The party consisted, in addition to the assistants, of about thirty 
men, seventeen of whom were enlisted men of the 2d infantry. While waiting for the Fur 
Company at Fort Union to build a Mackinac boat, animals and wagons were purchased, and the 
whole party explored the left bank of the Yellowstone to the mouth of Powder river. On the 
return a skin boat was made, and Mr. Hutton sailed down the Yellowstone to its mouth, making 
a map of the stream. On starting down the Missouri on the Ist of September, the wagons 
were disposed of, and all the property, stores, and collections placed in the Mackinac boat. 
The animals were conducted along the river by seven men, and camped every night with the 
boat. A halt of one day, and sometimes of two, was made at the mouths of streams coming 
into the Missouri, and at other important localities, where, by means of the animals, careful 
examinations were made. We arrived at Fort Pierre on the 2d of October, where the 
expedition terminated. 
BRIEF STATEMENT OF THE EXPEDITIONS THAT TOOK THE FIELD IN 1857. 
The United States astronomical and surveying parties for establishing the boundary line 
(49th parallel) between the United States and Great Britain, of which Archibald Campbell, 
esq. was commissioner, and Lieutenant J. G. Parke, Topographical Engineers, astronomer, 
was organized under the State Department, and started for the field of operations on the 
Pacific coast in April, 1857. 
The party under Mr. W. H. Nobles, organized in the Interior Department for making a road 
from Fort Ridgely to the South Pass, examined the route during the summer as far west as the 
Missouri, at the mouth of Crow creek. 
The party under Lieutenant Warren, Topographical Engineers, organized by the War 
Department, started in June in two divisions—one from Omaha city, the other from Sioux 
