524 DESCRIPTION *OR THE COUNTRY 
feet of conglomerate, such as usually accompanies the trap-rocks further to the 
north. 
Half a mile below Lac Travers a range of compact greenstone trap crosses Snake 
River, bearing northeast and southwest. The rock is traversed by many veins of 
calcareous spar, from a fourth of an inch to two inches thick, but no accompanying 
metal was discoverable, so far as they are exposed to view. 
The soil overlying this trap range is of good quality, and supports a dense growth 
of maple and other varieties of hard wood timber. From the former, the Indians 
manufactured in this vicinity considerable quantities of sugar. 
A few hundred yards below the lake, the elevation of the trap is about eight 
feet ; nearer the lake, fifteen feet, the bearing northeast and southwest. In litholo- 
gical character it is similar to the range three miles above the mouth of Kettle River, 
and appears to be its southwestern extension. At both these localities the trap is 
accompanied by brown amygdaloid, and intersected with spar veins. The cavities 
of the amygdaloid contain epidote and a green mineral, nearly as soft as tallow, 
when first collected, but brittle after exposure to the air. The rocks are much 
broken and shattered, and disintegrate rapidly by atmospheric agencies. 
Lac Travers is a fine sheet of water, four to five miles in length, and about three- 
fourths of a mile in width, the long diameter running nearly north and south. The 
shores vary from three to eight feet in height, and bear a heavy growth of pine. 
For five miles beyond this lake the lands bordering Snake River are low and 
wet, the growth pine, tamerack, aspen, elm, soft maple, and lind. 
Lake Pokegoma is situated about six miles above Lac Travers, and has an outlet 
into Snake River about one hundred feet wide. It is a beautiful expanse of water, 
about five miles in length, and upwards of a mile in breadth. The shore on the 
south is from ten to twelve feet high, and is lined with boulders of granite, syenite, 
and porphyritic trap. On the east, west, and south there are gradual wooded 
slopes. 
For twenty-one miles we observed no rocks in place. The first exposure that we 
encountered after leaving Lac Travers is three miles above Fishing Creek, where 
eleven feet of a coarse, gray, thin-bedded sandstone shows itself, some of which 
has rounded quartz pebbles disseminated. It dips with a considerable angle to the 
northeast. 
From an Indian village which is nearly opposite Fishing Creek, the land rises 
gradually to the height of fifteen to twenty feet. Some of the layers of sandstone 
a few hundred yards above, where they first appear, contain pebbles of granite, 
porphyry, jasper, and brecciated quartz. The dip of the strata, a quarter of a mile 
above, is about 5° to the northeast, but increases in proceeding up stream. <A short 
distance further, near where Knife River crosses Snake River, I found the succes- 
sions as follows : 
1. Thick-bedded, coarse-grained, gray sandstone, with siliceous pebbles disseminated. 
2. Thin beds of the same, with coarse pebbles. 
3. Thin layers of a kind of inferior red pipestone. 
This locality is about a quarter of a mile below the confluence of Knife River, a 
