TOPOGRAPHICAL REPORT ON WESTERN DIVISION. 209 
The basalt in these walls is columnar. A range of high bleak hills (the continuation of the 
divide) is on the right of the trail, and about two miles from it. For the last five miles the 
country is rough, broken, barren, God-forsaken, and desolate. Off to the southeast it presents the 
same dreary, desolate appearance. From Wah-wuk-chic river to the forks of the Sahpenis the 
country is covered with open pine woods, timber large, and no underbrush; fine grass grows 
in the woods throughout this distance. The Sahpenis is thirty-five feet wide and two feet deep, 
ford good ; this river has no valley at or above the ford, but the basaltic spur ceases on the left 
bank half'a mile below, and the valley widens out into a low, sandy, gravelly plateau several 
miles wide. 
A second stream, the Simkwee, comes into this valley from the northwest, and unites with 
the Sahpenis four miles below, forming the Pises river. The distance between these streams 
along the trail is three miles. The intermediate country is filled with arroyas, and has the 
appearance of being swept over in the wet season. Its soil is very sandy and gravelly; wild sage 
and wild rye grow upon it. A little cotton-wood and maple grow in the valley of the Simkwee, 
and some wide-spreading and scrubby white-oak along the banks of the Sahpenis. The Simkwee 
is twenty-five feet wide and eighteen inches or two feet deep; current rapid—ford good. From 
the crossing of the Simkwee the trail runs nearly north for eight miles, to the Atahnam, crossing 
a spur running to the east. This spur, and the one before reaching the Sahpenis, are the first 
of a series of radiating spurs which run off to the east from the main range of the Cascade 
mountains, between and separating the several branches of the Yakima. These spurs, or 
ranges, proceed to the eastward far beyond the trail, and fall off and lose themselves in the 
wide, worthless sage barrens along the Columbia river. This is a high, barren, and basaltic 
spur; the slope towards Simkwee and the summit being perfectly covered with sharp, angular 
fragments of loose, broken lava of all sizes, rendering the travelling hard upon animals. The 
slope towards the Atahnam is more earthy; ascent and descent abrupt. The Atahnam jis a rapid 
stream, forty feet wide and two and a half deep. The Atahnam has a valley of one quarter to 
half a mile wide at the ford, but the river is very crooked, and cuts it up, by its transverse 
crossings, into small, worthless patches. There are columnar basaltic walls on each side of it 
about thirty feet high, with high, rutted, earthy, and sandy hills piled on top of them. From the 
ford the trail bears to the east through the valley for three miles, to the Atahnam mission. Up 
to this point the valley is similar to that described at the ford; but below it the basaltic walls 
cease as the valley widens out. Thence the trail runs nearly north for about thirty-seven miles, 
to Ketetas, on the Yakima, crossing the Kwiwichess, Nahchess, Wenass, and Entinum, at 
intervals of seven, ten, seventeen, and twenty-seven miles, respectively. Between the mission 
and the Kwiwichess there is a high spur almost destitute of vegetation, and covered with 
immense fields of small, broken lava; ascent and descent pretty abrupt, and the top or summit is 
a rolling, broken plateau. The Kwiwichess is a small brook, from ten to fifteen feet wide; it forks 
a quarter of a mile above the ford. Its valley is a sort of basin, surrounded and terminated by 
the mountain on the west, and about three miles from the trail, and widening towards thé east 
until it reaches the Yakima. A little willow and aspen grow upon its banks, and there is good 
grass in the valley. A sharp spur of the Cascades runs between the Kwiwichess and the 
Nahchess. Many large masses of crumbling columnar basalt occur upon it. ‘The trail, however, 
is good. The descent to the Nahchess valley is quite abrupt and rocky. Fine grass grows 
upon this range. The valley of the Nahchess is from two to three miles wide at the point of 
crossing it, but widens towards its junction with the Yakima. It is very much cut. up by the 
crookedness of the river. Wild-cherry scrub, cotton-wood, balm of Gilead, and aspen, grow 
upon its banks. The river is seventy feet wide, but is one hundred yards wide at this point in 
the rainy season; it is three feet deep, and the bottom is filled with water-worn pebbles; current 
rapid, with great fall. In the hills on the north of the valley of this river is white, stratified sand- 
stone. The country between this river and the Wenass is over a high, rolling table-land, covered 
27 f 
