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or structural features. From cast to west these provinces are as
follows:

(1) An eastern or plains province extending westerly from Fort
Nelson for about 57 miles, and underlain by nearly flat-lying,-soft,
sandy shales of Lower Cretaceous age.

(2) The Foothills belt, about 50 miles wide, consisting of a
deeply dissected Tertiary peneplain; the foothills are underlain by
little disturbed Cretaceous shales and sandstones in the cast, and
by faulted and folded Mesozoic and Palacozoic formations in the west.

(3) The Rocky Mountain section, as traversed diagomally by the
Highway, is about 110 miles long and extends to Liard River. The
mountains of this belt rarely reach 8,000 feet above soa-lovel, but
are similar to the more southerly Rocky Mountains in structure and
rock components. The geological section comprises thick formations
of Precambrian and Palaeozoic age.

(4) Westerly for 20 miles, along the north side of Liard River,
the Highway crosses truncated ridges extending northward from the
Rocky Mountains. These are separated by extensive valleys. This
physiographic province terminates approximately at Smith River.

(5) The last province traversed extends from Smith River for
120 miles to Watson Lake in Yukon, ond is a rolling plateau deeply
covered with sand and gravel, and varied by low, rounded hills and
deep stream valleys.

The last two provinces mentioned are underlain by Palacozoic
rocks that here and there form the foundation for Tertiary lake and
swamp, clay and lignite deposits. busi

The Eastern Plains

For about 57 miles west from Fort Nelson the Alaska Highwoy
traverses a gently undulating plain, below which Muskwa River and its
tributaries have carved valleys 200 to 400 feet deep. The plain varies
in elevation from about 1,800 feet in the west to about 1,500 feet in
the east. The Kledo branch of the Muskwa has a wide, flaring valley,
whereas Muskwa Valley itself is deep with steep sides. Near its mouth
the river is nearly 400 feet below the adjoining upland. Fort Nelson
River Valley at this locality is broad and well graded.

Rock outcrops are few in the plains section. Along the small
stream that crosses the Highway through the R. Melville Smith Con-
struction Camp at mile gl, dark sandy shales outcrop for 200 to 500

L Mileages, unless otherwise mentioned, are measured west from zero,
the junction of the Highway from the south with the east-west road
from Muskwea and the Fort Nelson Air Port, 7 miles west of Fort Nelson.

feet to the flat top of a small hill. These shales are flat-lying and
contain small concretions. A well was drilled for water just cast of
the creek, to a depth (when visited) of 208 feet, and black. shale con-
tinued to that depth. No water was found, and porous, sandy members
were not encountered. Nineteen miles farther west, at mile 27, black
shale is exposed in a road cut. At mile 50 nearly flat-lying black
shale is exposed in the eastern flanks of the hills along the western
side of Kledo River Valley. These are described under the Foothills
province. To the south of mile 39, a large shale bank may be seen
flanking Muskwa River. Availeble evidence indicates that the eastern —
plains are underlain by nearly flat-lying sandy shales or shaly sand -
stones of Lower Cretaccous age. An examination of the valley of Muskwe