BIOLOGICAL RECONNOISSANCE AT FLATHEAD LAKE. 101 
down from shore. At the upper end, around the inlet, there has been 
some filling, but it has been slow. The depth a few hundred feet from 
the inlet was 30 feet, but it shot down rapidly to 115 feet, and finally to 
250 feet, the deepest recorded. This depth was taken opposite the rocky 
cliff toward the upper end, but a glance at the map of the lake will show 
it is everywhere deep. But a few feet off shore near camp at the southern 
end the depth taken was 165 feet. 
There is but one inlet, at the upper end, draining the eastern slopes 
of Sinyaleamin mountain and the Jocko peaks where there is abund- 
ance of snow the year through. There are no small inlets save when 
the snow is melting off the hills in the spring, but there must bea 
little underground seepage, as there is considerable water on the 
mountain sides high up that disappears before the stream reaches the 
lake. 
The stream forming the inlet comes through a canyon from the north, 
Sinyaleamin mountain forming the western wall, one of the Jocko peaks 
the eastern. Along this creek for a quarter of a mile or so there is a 
rank growth of beautiful arbor-vitae trees, as shown in the illustration. 
See Plate XXV. These continue until the canyon becomes so narrow there 
is room only for the stream, which tumbles over a cascade several hun- 
dred feet high, a portion of which is shown in Plate XXVI. This cascade 
was followed for some distance and as far as could be seen or heard tha 
cascade continued. Later, from the summit of the mountain, the direc- 
tion and source of the stream was determined. 
On account of the land locked position of the lake it is seldom disturb, 
ed by storms, although some strong gusts blow in from the west. The 
surface is usually calm and smooth, timber growing to the water’s edge; 
making a beautiful reflection. It appeared from indications along 
the shore that the surface of the water in the lake varied some three or 
four feet, at the time of our visit being at its lowest. There is very little 
drift in the lake. At the outlet there is quite a pile of old logs that have 
come down, but they show evidences of long submergence in the water, 
and are not in great quantity considering the timber around the lake. 
The shores are free from drift. 
Three ridges lead up from the base to the summit of the mountain, 
all of comparatively easy ascent. The ascent of the mountain from 
the lake, whose altitude is 3,800 feet, was made in a day, returning very 
late at night. We almost failed making it though within sight and hearing 
of the camp. This summit is really a long ridge, extending southeast and 
northwest, culminating in two peaks, and joined to the remainder of the 
range to the north by a low spur at the easternmost of the two peaks. 
On the north the drainage is into the main branch of Mission creek. Tha 
western peak drains into the stream below Sinyaleamin lake. The 
drainage from the country to the eastward and soutaward, as shown in the 
illustration, see Plate XXIII, is into Sinyaleamin lake. 
On the 12th of July, 1900, the ascent of Sinyaleamin mountain was 
made. The start was made before seven in the morning, three of us pre- 
paring our loads for the ascent. The outfit consisted of a camera with 
15 plates loaded, a rifle, a shotgun, a botany can, provisions for a day, and 
