EXPLORATION FROM A. D. 1852 To A. p. 1857. 67 
McClellan, Engineers, began at Fort Vancouver, on the Columbia, operated northeastward, 
examining the passes of the Cascade range ; and then eastward to join Governor Stevens’ 
party. Another party, under Lieutenant A. J. Donelson, Engineers, examined the Missouri 
river from its mouth to the Yellowstone, where a junction was made with that under 
Governor Stevens. The fourth party, under Lieutenant R. Saxton, U. S. Art., conducted a 
reconnaissance from Fort Walla-Walla to the Bitter Root valley, where a depot was established. 
The party under the immediate supervision of Governor Stevens took the field at St. Paul's 
on the 8th June. The principal engineer and scientific assistants consisted of Lieutenant - 
C. Grover, U. S. Art.; Dr. George Suckley, surgeon and naturalist; Messrs. F. W. Lander and 
A. W. Tinkham, civil engineers; Mr. J. Lambert, topographer; Mr. J. M. Stanley, artist; Mr. 
G. W. Stevens, assistant astronomer; and Mr. J. Moffett and Mr. J. Doty, meteorologists. 
Governor Stevens failed in securing the services of the officer designed to take charge of the 
astronomical observations. 
The party was well supplied with suitable instruments. Odometers, compasses, barometers, 
thermometers, sextants, chronometers, and a portable astronomical transit of twenty-six inches 
focal length, (which latter was not used.) 
Governor Stevens and party left St. Paul June 8, and crossed the Mississippi at Sauk 
Rapids. Several other crossings were examined for railroad bridges. 
They then took the Red river trail, and, on arriving at Pike lake, Lieutenant Grover was 
detached to make a side reconnaissance. 
The main party proceeded to make an examination of the railroad line to Fort Union, 
crossing the Shayenne river twice and passing some twenty-five miles south of Miniwakan lake. 
Mr. Lander also made a reconnaissance of the valley of the Shayenne river between the two 
crossings; also of a portion of the Cóteau du Missouri, some twenty miles westward of the 
general route, and of the upper valley of Mouse river. 
Lieutenant Grover, on being detached, examined a route from Pike lake towards Moose 
Island lakes; thence deflected to the south, and followed up the eastern bank of Lake Travers 
and Bois de Sioux river; thence by the Dead Colt Hillock and Butte des Os, and through the 
valley of Mouse river to Fort Union. His trail joined that pursued by the main party on 
Mouse River valley. During the reconnoissance he was supplied with odometer, compass, and 
meteorological instruments. 
Lieutenant Donelson and party—consisting of Lieutenant John Mullan, 1st artillery, Mr. Wm. 
Graham, and six enlisted men—left St. Louis in a steamboat on the 21st of May, and arrived 
at Fort Union, on the Missouri river, July 3. On the passage a reconnaissance of the river 
was made. Astronomical observations with a sextant, and meteorological observations with a 
barometer, being taken. Collections in natural history were also made. The topographical 
sketches of this examination were mostly lost afterwards on the Isthmus of Panama, and the 
map was made from incomplete notes. 
While waiting the arrival of Governor Stevens, Lieutenant Donelson reconnoitred the country 
in the vicinity of Fort Union, travelling northwest to a point about opposite the head of the 
Big Muddy, then nearly northeast to the Grand Coteau, at a point near the head of the White 
Earth, then nearly southwest to that stream, then down it a few miles, and thence back to Fort 
Union. This examination was made without a barometer, and distances were estimated. 
On the 9th of August the expedition moved from Fort Union in two parties. One under the 
command of Lieutenant Donelson, intending to examine the route near the forty-ninth parallel, 
and the other to take the route of Milk river travelled by the American Fur Company’s wagons. 
