LETTER TO LIEUTENANT MULL AN. 61 



struck the Missouri there is a very excellent prairie road leading westward ; but being unable 

 to ford the stream where I struck it, I was compelled to follow down the course of it for eight 

 miles to find a ford, and then crossed a high ridge of mountains west of the Missouri, in order 

 to cut off the distance to my left. This prairie extends about twenty miles to the west, to the 

 dividing ridge, where rises the main fork of the Bitter Boot river. This dividing ridge, from 

 which flow the waters of the Missouri and the Columbia, I crossed on the second day from the 

 Missouri, and it proved the only difficult point of passage in my route from Fort Benton. This 

 divide is about four hundred feet high, and about three miles across. I here fall upon the 

 headwaters of the main fork of the Bitter Boot river, the valley of which I followed down till it 

 unites with the Blackfeet fork of the Bitter Root river at Hell Gate. This valley is about a mile 

 wide, and well wooded with the pine and cotton-wood tree, and affords a most excellent road 

 for the passage of wagons. There is a well-beaten trail along this valley, made by the Flat- 

 heads in their course to their hunting-grounds east of the Missouri. I would here mention 

 that this same trail leads along the north fork of the Muscle Shell river ; thence down the river 

 to its mouth. The grade of this valley is scarcely perceptible, and along it you pass along the 

 slope of but one mountain, which, with but little trouble, would allow wagons to pass over it. 

 After leaving the main fork, I crossed the Blackfeet fork of the Bitter Root, and followed 

 along it for six or eight miles, and thence crossed to the St. Mary s by a most excellent prairie 

 road. I found good grass and water for my animals on nearly the whole route, and slept but 

 one night without wood, which was between the Missouri and Muscle Shell. I would mention 

 particularly the valleys of the Muscle Shell and the main fork of the Bitter Root rivers, as being 

 well grassed. I found, in both valleys, the grass green, rich, and luxuriant, and water and 

 wood in abundance. This wood I found to be principally the pine, cotton-wood, spruce, cedar, 

 and hemlock. I would also mention that game in the greatest abundance is to be found along 

 the whole route buffalo, elk, antelope, and bear. I would also mention that I found the 

 weather much more mild west of the Missouri than east of it. For full details as to the char 

 acter of the country, for each day s march, and the streams and rivers passed, I would refer 

 you to my journal. 



I have the honor to be, sir, your obedient servant, 



J. MULLAN, 



Lieutenant United States Army. 

 Hon. ISAAC I. STEVENS, 



Governor of Washington Territory. 



No. 2. 



NORTHERN PACIFIC RAILROAD EXPLORATION AND SURVEY, 



Fort Oiven, St. Mary s Valley, October 3, 1853. 



DEAR SIR: You are placed in charge of the meteorological and supply post established in 

 this valley, with Mr. Adams and Mr. Burr, assistants; Sergeant Simpson, in charge of the an 

 imals; Corporal Rose, Privates Wolfe Williams and ToohilL Isham, of the 7th infantry; and 

 Simpson, Farnham, Osborne, Osborne, jr., Mechelbach, and Bell, quartermaster employes, and 

 Gates, to be chargeable to the survey. 



The object in establishing this post is twofold: first, to ascertain the character of the seasons 

 in this valley, and the adjacent ranges of mountains, by numerous and carefully-made meteoro 

 logical observations ; and, second, to continue the exploration and survey of the country between 

 the Ptocky and Bitter Root ranges of mountains, extending it to Fort Hall, to connect with the 

 survey of Fremont, and northward to the Flathead lake, and even to the upper waters of Clark s 

 fork. As much time as practicable should be given to the examination of entrances to passes. It 

 is believed you will be able to work late, and to resume operations at an early period in the spring. 



