FROM FORT BENTON TO WALLAH-WALLAH. 275 



connexion through here from Blackfoot river to Clark s fork, promising better than the Jocko 

 river. This summit I estimated could be easily attained, with a forty-foot grade, from the large 

 plain where we encamped on Sunday, 25th September. It is not a ridge, but a flat, or almost a 

 flat, with a sluggish beaver-dammed brook running through it, sometimes almost motionless. It 

 is very likely that the trail forked here ; but although I searched for it for a considerable time, 

 I could discern no crossing of the stream, and no certain indication that there was a division of 

 the trail. 



The approach to this summit is so easy, that I am encouraged to believe that a railroad line 

 will be obtained here which shall avoid the difficulties near Hell Gate, and the summit between 

 St. Mary s and Jocko river. 



I regret that I am not able to speak more positively on this matter. The route which I really 

 followed I considered to be every way practicable, but I think it goes altogether too far north, 

 and that it leads to Flathead lake, although of this I am not certain. It may be worthy of 

 remark that, in crossing over the mountains towards the British trading posts, there was a vast 

 amount of the finest limestone suitable for building, and lying in large square blocks, and 



stratified. 



Very respectfully, your obedient servant, 



A. W. TINKHAM. 



Lieutenant DONELSON, 



Corps of Engineers, Olympia, Washington Territory. 



EXTRACTS FROM MR. F. W. LANDER S REPORT OF FEBRUARY 15, 1854, TO GOVERNOR STEVENS, 

 GIVING THE RESULTS OF PERSONAL EXAMINATIONS, IN CONNEXION WITH THE RAILROAD SURVEY 

 OF LIEUTENANT DONELSON FROM FORT BENTON TO WALLAH-WALLAH. 



My own examinations extend through Lewis and Clark s Pass, and were abandoned at a point 

 seven and a half miles west of the summit of the pass. 



From the rapid descent from this pass towards the west, I was led to give my attention wholly 

 to the line extending west from Cadotte s Pass. My examinations upon the line of Cadotte s 

 Pass commenced at a point sixty miles west of the summit. (Mr. Lander s route was in fact 

 along the valley of Hell Gate river.) 



The ascent to Lewis and Clark s Pass can be made at forty (40) feet per mile. The minimum 

 curvature adopted in the approach is of fifteen hundred (1,500) feet radius. The tunnel is two 

 and three-fifths miles in length. Grades should descend from the eastern orifice of the tunnel 

 towards the west, in order to reduce inclination. 



The grade in descent towards the west is forty (40) feet per mile for about seven and a half 

 miles; minimum curvature, fifteen hundred (1,500) feet radius; from the point seven and a half 

 miles west by the present reconnaissance, a steeper inclination must be adopted. I am of the 

 belief that gradients of fifty (50) feet per mile can be secured. 



My own examinations have been upon a line through the valley of the Blackfoot fork [Hell 

 Gate river] and Bitter Root river, and Clark s fork of the Columbia, passing south of Lake Pend 

 d Oreille to the lower extremity of that lake, and thence in a southwesterly direction to the Great 

 Plain of the Spokane, thence by the northern bank of the Peluse to the northern branch of the 

 Snake, thence to the Columbia. (Mr. Lander s route left the Blackfoot river some distance 

 down the trail, crossed the mountain spurs to the south into the valley of Hell Gate river, and 

 then followed that river down. The railroad practicability, therefore, of which he speaks, is of a 

 portion of the Hell Gate, and not of the Blackfoot trail. Hence, whenever Mr. Lander speaks of 

 the Blackfoot trail, he must be understood as really describing the Hell Gate valley; and Hell 

 Gate will accordingly be substituted in brackets for Blackfoot.) 



From the point where rny own examinations commence, the general descent of the Blackfoot 



