186 PASS OF THE COLUMBIA RIVER. 



age of the mountains, was generally clear and very cold. Immediately after reaching the west 

 ern slopes the weather became milder, soon damp, and finally, after passing Snoqualme Falls, 

 rainy. 



The whole breadth of snow over twelve inches deep was some less than sixty miles in extent. 

 Of this about forty-five miles were two feet and upwards ; about twenty miles were four feet and 

 upwards ; and six miles were six feet and upwards. 



All of the snow was light and dry ; it was the accumulated snows of the winter to January 21, 

 deposited in successive layers of from a few inches to two feet deep, which had generally lain 

 undisturbed since their fall; and they present little obstruction to removal in comparison with 

 the compact, drifted snows of the Atlantic States. 



The Yakima Indians with me, who were well acquainted with the route both in summer and 

 winter, cached their snow-shoes only eighteen miles west of the summit, to be used when they 

 went back to their country. They could not return there until as late as February 10, and evi 

 dently, at that place, expected no increase of snow during the interval of their absence. 



I see no well-grounded reason to apprehend that the regular running of railway trains would be 

 hindered in winter from the snow in the Yakima Pass. 



My exploration was made for the purpose of getting the winter condition of the pass ; and, 

 as you are aware, I had no white man with me. I had previously been obliged to abandon my 

 barometer and thermometer. I had with me only a pocket-compass, and, under the difficulties 

 with which all such winter explorations are attended, could accomplish little more than what I 

 have here set before you. 



From opinions of the route while passing over it, I think it probable that, with the shorter 

 tunnel proposed by Captain McClellan 2.27 miles in length we shall be able to pass the sum 

 mit with eighty-feet grades for a limited distance, say fifteen miles, or seven and a half miles 

 ascent and seven and a half miles descent. 



I am, respectfully, your obedient servant, 



A. W. TINKHAM. 



Governor I. I. STEVENS, 



In Command of Northern Pacific Railroad Survey, &{c. 



6. REPORT ON THE RAILROAD PRACTICABILITY OF THE PASS OF THE COLUMBIA RIVER, BY MR. 



F. W. LANDER, CIVIL ENGINEER. 



OLYMPIA, WASHINGTON TERRITORY, 



January 5, 1854. 



SIR: The high floods to which the Columbia river is subject are serious obstacles to obtaining 

 the best location for cheap construction offered by its valley. From the danger to be appre 

 hended from them, it will be necessary to place the bed of the road at some distance above the 

 ordinary level of the water, and thus incur the need of cutting deeply in many spurs and ledges. 

 I am of the opinion, however, that the general grade of the road will not exceed ten feet per 

 mile; and the facilities for borrowing from the debris of the neighboring ledges a material needing 

 no tool but the shovel, and the long stretches of prairie and bottom land that occur where an 

 embankment road-bed may be used, protected from the action of the water by the simple means 

 of placing the weightier material at its natural slope on the outer edge, will materially reduce cost. 



At eastern prices, the whole of this work, with the due amount of protective material, could 

 be constructed at fifty cents per cubic yard ; and, when built, would be unequalled in the grand 

 points of facility of drainage and preservation of superstructure. 



It may become necessary to tunnel the mountainous point termed Cape Horn. Passing this 

 point by water, I was not able to obtain so fair a view of the opportunity afforded for the adjust- 



