35°

V. DOLMAGE.

is situated so that the northeast corner lies a few miles south of
the town of Telkwa, on the Grand Trunk Pacific railway, at a
point about 300 miles east of Prince Rupert. The only means
of communication between the interior parts of the district and
the railroad are two wagon roads and a number of trails.

tO POGRA PEL.

The country is mountainous, lying about on the boundary of
the two physiographic provinces known as the Coast Range sys-
tem and the interior plateau. It is bounded on the west by a
rugged spur of the Coast Range and on the east by the broad
valley of the Bulkley River. In the centers of the east and west
halves of the area are two similar and roughly circular groups
of mountains, separated from each other and from the Coast
Range by deep glacial valleys of the type known as “through
valleys.” These valleys cut sharply into the gentle slopes of an
old mature erosion surface and have the peculiarity of extending
through to adjoining drainage systems with very low divides,
usually flat and marshy. Each of the two mountainous areas
reaches an elevation of about 8,000 feet, and the Coast Range
rises to about 9,000 feet. The Bulkley valley in this district is
below 2,000 feet. Each of the mountain masses has radial
drainage and the streams occupy deeply cut glacial valleys which
head in cirques, many of which are still occupied by active gla-
ciers. The cirques extend well back to the center of mountains
in many places being separated only by sharp arétes, indicating
that the glacial cycle of erosion has developed to a mature stage.

GEOLOGY.

The geology of the area is directly related to the topography
since each of the three mountainous areas has at its core an in-
trusion of plutonic rock, which cuts through the old tufts of the
Hazelton formation.

The oldest rocks of the district make up the Hazelton forma-
tion, which is thought to be Triassic or in part Jurassic in age.
The formation has an areal distribution of many thousands of
square miles in northern British Columbia, and a total thickness