78 FIELD PARTIES AND OPERATIONS. 



by the movement of the train, and on which were to be made the observations ; and, by detached 

 parties, to examine important land-marks and side-routes, and cover as much of the country as 

 practicable. Such a general knowledge was thus to be gained of the country as will give the 

 means of giving locations of roads, with approximate estimates of cost. 



On reaching Pike lake, on the Red river trail, Lieutenant Grover, in command of a select party 

 of nineteen men, was detached to examine a route to Fort Union, by Dead Colt Hillock, whilst 

 the main party, under my own personal direction, examined a more northern route, crossing 

 the Shayenne river twice, and passing some twenty-five miles south of the Miniwakan lake. 



The trails of the two commands came together in the valley of Mouse river, and they reached 

 Fort Union without accident of any kind Lieutenant Grover on the 25th of July, and the main 

 party on the 1st of August. 



It is proper to mention that, in the progress of the main party, much was done in the way of 

 reconnaissance by the civil engineer parties. Besides the usual examination on the line, Mr. 

 Lander made a reconnaissance of the valley of the Shayenne river, between the two crossings; of 

 a portion of the Coteau de Missouri, some tw^ ,ty miles westward of the general route, and of the 

 upper valley f Mouse river ; and Mr. Tinkham, besides being in charge of the topographical 

 survey of the route, added materially to our knowledge of the course and character of the streams 

 by detached work. 



Lieutenant Donelson had already preceded the parties operating by land, had made the survey 

 of the Missouri to near the mouth of Milk river, and a reconnaissance of the country in the vicinity 

 of Fort Union. 



On the 9th of August the command moved from Fort Union in two parties, under the com 

 mand of Lieutenants Donelson and Grover ; the former to explore a route leading from the Mouse 

 River valley under the 49th parallel, and the latter to take the route of Milk river, travelled by 

 the wagons of the Fur Companies, and both to rendezvous at Fort Benton. 



At the Big Muddy river the two commands were united under my own direction, the topo 

 graphical survey of the route placed permanently in chirge of Mr. Lambert, and the Milk river 

 route pursued by the whole party till it approached within 155 miles of Fort Benton; when, 

 leaving the main train in command of Lieutenant Donelson, I went forward with two detached 

 parties, under Lieutenant Grover and Mr. Lander, and reached Fort Benton on the 1st of Sep 

 tember. 



Lieutenant Grover was, on the 5th, sent forward to cross the Rocky mountains, and ascertain 

 whether Lieutenant Saxton had established a depot at St. Mary s village, and Mr. Lander was 

 ordered to be in readiness to survey the Marias Pass. 



Lieutenant Donelson reached Fort Benton on the 6th of September, and Mr. Tinkham, who by 

 my direction had been assigned to the duty of making a general exploration between the Milk 

 and Missouri rivers, on the 9th September. 



Dr. Evans, the geologist of the exploration, reached Fort Benton on the 5th September, having 

 made a large collection in the Mauvaises Terres, and reconnaissances of the country south of the 

 Missouri and Yellowstone, and between the Milk and Missouri rivers. He left Fort Benton for 

 Oregon, September 10. 



Without noticing minor changes of programme, it will be sufficient to state that Lieutenant 

 Grover met Lieutenant Saxton near the dividing ridge, and that both reached Fort Benton on 

 the 13th September, with information of the establishment of a depot at the St. Mary s village ; 

 that Lieutenant Grover was assigned to the duty of completing the survey of the upper Missouri, 

 and of crossing the mountain chains in winter with a dog train, to ascertain the condition of the 

 snows ; that a meteorological post was established at Fort Benton, in charge of Mr. Doty and 

 three men ; that the wagons were left in store there, and much other public property ; that Lieu 

 tenant Saxton went down the Missouri with enlisted men and employes not needed to continue 

 the survey, with orders to repair to Washington city ; that the Flatheads were visited at their 



