Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 1, Pt. 2

TOPOGRAPHICAL REPORT ON WESTERN DIVISION.
the waters of its principal tributaries, Atahuiam, Nahchess, &c., the country along the Yakima
river from its sources in the mountains to its junction with the Columbia. From Ketetas northerly to the mouth of the Pisquouse or \Neniatshapam; thence, up the Columbia to Fort
Okinakane, the country on the Methow river from its head to its mouth, the country along the
Okinakane river from its junction with the Columbia to the lakes beyond the forty-ninth parallel;
thence, leaving the Okinakane at its forks, eastward across the country to the Nehoialpit river;
thence, down this river to its mouth, crossing the Columbia at Fort Colville. From Fort Colville
to Fort Wallah-Wallah, via the valleys of the Slawntehus, Chemakane, Cherahna, and WallahWallah rivers, crossing the Spokane river a few' miles below the forks or site of the old Spokane
house, and the Saptin or Lewis' fork of the Columbia at the mouth of the Peluse; thence, down
the south bank of the Columbia to the Dalles, and from the Dalles down the Columbia river
by water to Fort Vancouver.
The country gradually rises back of Vancouver into a light range of hills running parallel
to Columbia river, and generally about a mile and a half from it. Two miles from Vancouver
the trail crosses a brook twenty feet wide, which empties into a lake three miles below that
place; the lake communicating with the Columbia ten miles below. From this stream the country along the trail breaks into small openings or plains having no timber on te. They
vary from a half to several miles in extent, are very level, as well as the adjacent country,
and are separated from each other by narrow stripl)s of woodsf Kolsas, the lar'gest of these
plains, about sev('n miles from Vancotiver, is Mix or seven miles lont,. and three or f)ur in breadth,
and connects on the south with a swanipy arm of Camnas plain, which stretches off to the eastward, in which direction there is a large tract of the same character of country lying along ill
creek, and running down towards the Columbia. From Ko]sas the trail bears to the northeast
for six miles to a plain called Simsik, about a mile and a half long. The country between
Vancouver and Simsik is similar in character-heavily timbered with fir, spruce, and a dense
undergrowth of maple and hazel bushes. The soil is sandy and gravelly, especially the open
plains; the soil in the woods between Kolsas and Simsik is thle best. The countrity up to
Simsik is quite level; leaving Simsik east of north the country becomes hilly and broken along
the trail, the hills becoming higher and more rocky as we approach the Cathlapoot'l river.
Between these points the trail crosses several branches of the Cathlapoot'l. Six miles from
Simsik there is a small rapid [)rook fifteen feet wide; two miles farther on there is another, thirty
feet wide and two deep; and a third, the Yahkohtl, eight miles beyon(i, about forty feet wide
and two and a half deep.'The bottoms of these streams are rocky, and that of the Yahkohtl
very stony; the currents rapid. They run among high hills, and have no valleys. They unite
a short distance below the fords, the main stream uniting with the C athlapoot'l four miles from
its junction with the Columbia. Eleven and a half miles from the Yahkohtl the trail crosses
the Chalacha. This river is thirty-five feet wide, ford good. It receives two branches a short
distance below the fobrd -the first from:the southeast, a bold rapid brook twenty feet wide; and
the other a small rivulet coming in from the other side and running nearly parallel to the Chalacha,
and one and a half or two miles from it. Thirteen miles from Simsik is Mankas Plain, surrounded
by hills, and more low and swampy than the other plains met with. Six miles beyond the Yahkohtl river is the Yahkohtl Plain, a high, sandy, undulating plain, about three miles long. Five
and a half miles beyond this plain occurs the Chalacha Plain, lying between the Chalacha river and
the parallel rivulet before spoken of. The country between Mankas and Simsik is simply hilly;
hills higher near the latter place. Between Mankas and the Yahkohtl river there are two sharp
spurs of the Cascades. differiuJg firom the other hills by being higher and rocky. They stretch off.
to the east and west, increasing in altitude towards the east, but falling offin the opposite direction.
Between the Yahkohtl and Chalacha rivers the countly is high and hilly, and, in places, much
broken. There is a high spur running along the left bank of the Chalacha river, and the plain of
this name is entirely surrounded by high ridges and rocky peaks. An almost perfectly symmetrical
204