104

mouth with respect to the main valley shows that it was formed before the
main valley was deepened to its present extent. If the valley had been
formed at the same time as the deep part of the main valley it would have
been graded to the bottom of the main valley. The slide rock in the bottom
of the valley is, therefore, probably preglacial, as well as the placer gold
which occurs mainly in the bedrock gravels and in crevices and depressions
in the bedrock. Part of the gold, however, may have been deposited along
with the glacial gravels which extend nearly down to bedrock, and after-
wards have been concentrated in the bed of the channel. There is said to
be a pay-streak also in the drift some distance above the bedrock. This
pay-streak may be interglacial in age and may be the result of stream
erosion of the glacial drift and concentration of the gold in it. Practically
all the materials overlying the bedrock, as exposed in the sections at the
head of the hydraulic pit, are clearly glacial in origin. They consist mainly
of poorly stratified gravels, interbedded in places with thin layers of silt
(slum). Near the top on the sides, the valley filling is boulder clay which in
most places is only a few feet thick. The top few feet in the central part con-
sist of Recent alluvial deposits of sand, fine gravel, and muck. The materials
filling the valley are, therefore, easily hydraulicked out, the main difficulty
being that there are numerous large boulders near the base of the deposits
which require blasting before they can be put through the sluice boxes.

The broad, drift-filled channel extending from the head of Stouts gulch
to the head of Lowhee creek is a unique feature in the district and has been
generally regarded as evidence of an old high-level stream channel coming
from the upper part of Williams creek or from the upper part of Conklin
gulch’. Hydraulicking in Stouts gulch was carried over the summit as far
as grade could be obtained and some gold was found in the channel on the
summit. It is uncertain whether the gold occurred on bedrock or was
derived from the glacial drift filling the channel, for in hydraulicking it is
frequently difficult to tell just where the gold is coming from. The valley
filling near the summit is mostly boulder clay, but some gravels occur and
there is a small thickness of alluvium at the top. The bedrock where
exposed by hydraulicking shows no evidence of glacial erosion, but it is so
soft that evidences of glacial erosion would not have been preserved. The
broad, flat-bottomed character of the channel, however, and the occurrence
of boulder clay extending down in places to bedrock, suggest glacial ice
erosion of the bedrock to some extent. J udging from the topography it is
quite possible that a branch of the Williams Creek glacier passed over the
summit and widened and deepened it to some extent. It is probable that
the ancient valleys of Stouts gulch and Lowhee creek headed close together.
It may be that the summit channel represents all that is left of the channel
of an ancient stream flowing at the level of the pass, but it seems more
probable that the channel was partly formed by glacial erosion and also
Represents the divide at the headwaters of the two streams, Stouts and

owhee.

Placer mining on Lowhee creek (Figure 16) began in 1861 and has
been carried on to some extent nearly every season since that time. Mining
was first done in the shallow ground in the bed of the channel near where the

Go Raed J. B.: ‘Notes on the Placer Mines of Cariboo, British Columbia’”’; Econ. Geol., vol. XIV, p. 339