130 DR, D. LYALL ON THE BOTANY 
height of the floods eaused by the melting of the snow in the 
mountains, are almost entirely covered with water. From Sinyak- 
wateen, the crossing-place at the Pend Oreille River, the trail runs 
through a gloomy and almost grassless forest for about twenty or 
five-and-twenty miles to the Pack River, from whence to the Koote- 
nay the forest is more open. 
Along the valley of the Kootenay which ave ascended the forest 
is in most places open, with no scarcity of grass on the right bank. 
The valley above the place where crossed is very narrow, with steep 
hills in some places rising abruptly from the river. Above the 
second crossing of the Kootenay at its south-east bend, and on 
approaching the Tobacco Plains, the river-banks become more 
rugged and thickly timbered and grass more scarce, until, suddenly, 
what was nothing more than a ravine opens out into a wide, almost 
treeless valley, with many of its plants similar to those of the dry 
grounds of the Columbia. The trailleading to the Boundary Pass 
of the Rocky Mountains merely crosses the lower corner of this 
open valley and enters shortly amongst the Galton Mountains, a 
range lying between the Kootenay and Flathead Rivers, and rising 
to an altitude of about 8000 feet above the sea. Crossing by a 
- pass, which on the 17th of July had snow upon it, the trail runs 
down the eastern slope of the Galton Mountains to the Flathead 
River, which, at the place where it was forded, was found to be 
4005 feet above the sca. The valley of the Flathead is partly 
clear of trees, and again affords indications of a comparatively dry 
climate. Immediately on crossing this valley, the Pass of the 
Rocky Mountains is entered upon. The ascent is at first very 
gradual until, in the very centre of the range, a steep hill comes in 
the way, the pass over which was found to be 6970 feet above the 
sea, wooded on both sides and with scattered stunted trees on the 
top. On the east side of this hill there is a steep descent to a 
glen which leads out by a comparatively gentle decline to the 
Buffalo Plains of the Saskatchewan.- These plains, close to the 
foot of the mountains (the termination of which is very abrupt), 
are about 5000 feet above the sea. 
The camp of the astronomical station on the Rocky Mountains 
was at an altitude * of 6480 feet, close to the 49th parallel ; and 
from this the slaty summits of the mountains (8386 feet above the 
sea) could be reached, affording an excellent opportunity of form- 
ing a complete collection of the vegetation of this elevated region. 
* The altitudes given are from observations made by Mr, Bauerman, the Geo- 
logist of the expedition. 
