SALMON INVESTIGATIONS IN COLUMBIA RIVER BASIN IN 1896. 43 
along over level ground, we might expect to find that part of the lake where the land- 
slide was deposited more shallow than elsewhere; but, on the contrary, we find a 
depth of water varying from 50 to 70 feet, which corresponds with depths found in 
other parts of the lake the same distance from the shore. It seems more reasonable 
to suppose that at some distant period the ground on which this forest grew, subsided. 
This, in a measure, would account for the trees being left standing in their natural 
position. Not having seen any portion of the submerged forest, we are not able to 
state from personal observation anything concerning it, only stating what has been 
given by several reliable parties. Efforts were made to locate some of the trees, but 
none of them could be found with the sounding line. 
Depth of tvater and character of bottom . — Lake Sammamish is quite uniform in 
depth, varying from 70 to 90 odd feet in the middle and from 35 to 50 feet near the 
shore. The deepest sounding was found near the middle of the lake, about halfway 
across from Hattie Bell Springs to the west shore. A line of soundings run across 
the upper part a short distance below the shingle mill corresponds nearly with the 
line across the south end of the lake. In no part of the lake examined are there indi- 
cations of plateaus or shelves making off from the shore. Only in a few places was 
shallow water found, and this extended but a short distance from the shore. In nearly 
all parts of the lake along its margin the bottom drops off suddenly, the water being 
deep enough for boats and small steamers to lie alongside and discharge freight or 
passengers. 
From 80 to 100 feet from the shore is the average distance where the sand and 
gravel merge into the hard or soft mud. A number of places, however, were found 
where sand and gravel bottom extends from 125 to 300 feet into the lake; one of these 
places is on the west side, opposite Hattie Bell Springs, and the other off the wharf 
on which the sawmill at Monohan is built. 
At the foot of the lake, above the shingle mill, the bottom is very soft and in the 
center between the east and west sides the mud is said to be several feet deep, and this 
statement is probably not exaggerated, for in running the line of soundings which ends 
just below the shingle mill the sounding lead, nearly all the way across, sank into the 
soft bottom a foot or more. 
Inlets . — Numerous small creeks empty into the lake both on the east and west sides, 
but the discharge of water is not great even during the rainy season, and in summer 
many of them dry up, they being fed by the drainage from the surrounding hills. The 
principal inlets are Issaquah and Manner creeks, which enter the lake on the south 
end. The main portion of the first creek is 2 miles long and the second about 3 miles, 
each having several branches from £ to 2£ miles long. The water in Issaquah Creek 
is said to be very clear during the summer and fall months, or was previous to the 
coal company using the creek as a dumping-ground for coal screenings, since which 
time the water has become muddy. There are a number of coal mines in this region, 
and the people complain of the screenings from them being dumped into the creeks, 
thereby doing considerable injury to the fishing grounds. 
Outlet . — Squak Slough, or Sammamish Biver, is the only outlet to the lake. This 
at times is not large enough to prevent the water in the lake from rising rapidly, and 
when Lake Washington rises at the same time, which is usually the case, and forces 
the water from the slough into Lake Sammamish, both lakes rise rapidly. At the 
