58

The elevation of the bedrock in the lowest part of the buried channel
at the Bradford tunnel is 4,430 feet; the bedrock in the lowest part of the
hydraulic pit is 4,450 and the floor of the tunnel at Sawmill flat is 4,390.
The bedrock in the lowest part of the old channel in the hydraulic pit is
higher than in the deepest part of the buried channel where the Bradford
tunnel was run higher up and on the opposite side of the creek. An old
channel probably ran about where the tunnel is located, crossed the present
stream valley at the hydraulic pit, and continued on the north side of the
creek towards Sawmill flat; in the part along the Bradford tunnel it was
eroded to its present depth prior to the deposition of the glacial drift which
now fills it. The present channel of Antler creek below the hydraulic pit is
in part a rock canyon or rather a V-shaped gorge, and forms the only possible
outlet for the old channel. Therefore, it is probable that this part of
Antler creek also was formed, in part at least, before the deposition of the
latest glacial drift. The upper rock canyon is much narrower and is post-
Glacial in age.

As the tunnel at Sawmill flat is 60 feet lower than the bedrock in the
hydraulic pit, 700 feet upstream, it is probable that the tunnel is too low to
intercept the continuation of the old channel, for it is unlikely that the
grade of the channel is over 2 or 8 per cent. The old channel, however,
can not be more than 50 feet above the flat and the bedrock outcrops north
of the cabins at the flat show that the old channel does not extend past the
small stream coming in from the north. It is possible that the channel
in its lower part has been partly destroyed by glacial ice erosion.

Antler creek above Sawmill flat carries a good supply of water through-
out the season, and water for hydraulicking at Maloney flat, if the ground
is found to contain sufficient gold values to pay, can be obtained by a ditch
1 to 2 miles long, depending on the head required. The creek has a fall of
140 feet from Maloney flat to Sawmill flat, a distance of 1,300 feet, and has
a gradient of about 200 feet to the mile above Maloney flat. The old
China Creek ditch, in use up to 1915, leaves Antler creek about one-half
mile above Maloney flat. It is about 140 feet above the flat, but is partly
destroyed at places where it was flumed around the rock nose above the
flat.

The material overlying the old channel to a depth of 50 to 100 feet
along the course of the Bedford tunnel is mostly glacial clay. On the north
side of Maloney flat, a washout from China Creek ditch has exposed a
considerable body of glacial outwash gravels, which also occur in places
along the supposed course of the lower part of the old channel. The
section exposed in the hydraulic pit shows 20 feet or more of glacial clay
underlain by gravels.

A well-marked high-level channel parallels Antler creek on the left side
from the head of Wolfe (China) creek south to the great bend of Antler
creek. It is about 400 feet above the creek and is followed by China Creek
ditch. Bedrock outcrops on both sides of the valley at the reservoir about
midway, near the summit, where the valley bottom is less than 100 feet
wide. Near the south end the valley is drift-filled and the bedrock is
probably lower than at the reservoir. The valley appears to have been
formed, in part at least, by two streams flowing in opposite directions and
heading near the reservoir, but has been modified by the effects of glaciation.