346 REPORT AND ESTIMATE. 
If the short tunnel be used, the road at this point must leave the valley, take a side location 
on the northern slope of the mountains bordering the valley on the south, and ascend eight 
hundred and ninety-five feet in eighteen and a half miles, giving a gradient of 48345 feet per mile, 
in fifty per cent. rock. The plateau of Willailootzas, one mile long, will be entered by a curve, 
with a radius of about two thousand feet, and the road pass along the north bank of the lake, 
with side location in eighty per cent. trap rock, easily worked. This lake should be partially 
drained; its shores are steep and of broken stone. There will be some little difficulty in 
preparing a proper depot for the workmen, tools, &c., at the entrance of the tunnel; or, if the 
long tunnel be used, then, commencing at the point eighteen and a half miles east of Willai- 
lootzas, there will be eighteen and a half miles, with a gradient of 1512; feet per mile, and with 
but little side cutting, through a thickly timbered country as far as Kitchelus. 
Both tunnels will pass through solid rock, (silicious conglomerate,) and there will be cutting 
through rock of similar character on the mountain spur bordering the valley of the Nooknoo. 
Yellow pine grows abundantly on the Yakima ninety-six miles from its mouth, and can be 
rafted down at high water. Granite can be brought down from a point about one hundred and 
forty miles above the mouth of the Yakima, and good sandstone and limestone are to be found 
on Puget Sound. The question of snow has been sufficiently considered in the meteorological 
paper. 
Seattle is an admirable harbor for a great railroad depot, being land-locked, defensible, 
accessible, and commodious. The harbor at the entrance of the Snoqualmoo, or, as it is named 
in the lower part of its course, the Snohomish river, has mud flats, with a good harbor between 
the flats and Point Elliott to the south. The suggestion is whether the line may not follow 
down the Snoqualmoo on its north bend, cross over to Whidby's island, and the depot be estab- 
lished on its western shore, nearly opposite Port Townsend. This will require works of the 
largest and most expensive character; for an artificial harbor must be made, by a breakwater 
midway between the island and the opposite shore. When it is recollected that with such a 
breakwater—for such a form and position can be given to it as that a heavy battery, with a 
keeper's tower can be planted on it—the extensive waters of the sound could be defended by 
a single system of works at Port Townsend, the suggestion may not be altogether without 
significance. A small work would be, of course, required at Deception Passage. 
BRANCH ROAD DOWN THE COLUMEIA TO VANCOUVER, AND EXTENSION, VIA LINE OF COWLITZ, TO 
PUGET SOUND. 
On the map I have exhibited this branch as leaving the main trunk twenty miles before reaching 
the Columbia. This is not done as giving a location, but simply for convenience of reference. 
There should, if practicable, be but one bridge crossing by the Columbia for the two branches, 
supposing the branch down the Columbia should keep along its south bank, as minute surveys 
can determine the particular details. On the north side of the river the party of Mr. Tinkham 
found it necessary in only two instances to cross the rocky spurs which jut out from the river 
bluffs. The Columbia River Pass is not only undoubtedly practicable, but is remarkably 
favorable. The only tunnel required will be to effect the passage around Cape Horn mountain; 
this will not exceed seven hundred feet in length, and a close examination may prove even this 
= be unnecessary, There need be no gradient to exceed ten feet per mile, but considerable 
side cutting in the rock will be necessary. The high floods to which the river is subject are 
the most serious obstacles to obtaining the advantages of cheap construction offered by its 
valley; to avoid these it will be necessary to run the road at some distance above the water; 
