30
ff ;
from 20 to 50 feet in width. There are five other falls ranging from 6 to 50 feet
in height, which make the river quite unnavigable. In consequence of this the
_ regular canoe route follows a chain of eight small lakes lying to the east of Lock-
hart river?’ The total distance from the head of McKay lake to the mouth of
Lockhart river is about 300 miles.

Hoarfrost river empties into Great Slave lake on the north side by a fall 60
feet in height at a point where the adjacent hills are about 1,000 feet high. The
river has a very steep gradient and is full of rapids and falls. It rises in Walmsley
lake and forms a difficult canoe route through that lake to Artillery lake, a route
that was followed by Captain Back in 1833.*

Mackenzie River

The name Mackenzie river is applied only to that portion of the Mackenzie
River system extending from Great Slave lake to the Arctic ocean, a distance
according to Ogilvie, of over 1,000 miles. The total distance, however, from the
headwaters of the most distant tributary of Mackenzie river, namely the Finlay,
to the Arctic ocean, is 2,525 miles. .

The Mackenzie on issuing from Great Slave lake has a width of
7 or 8 miles, but is shallow and filled with islands between which a moderate
current flows. Fifteen miles down, the islands cease and the river contracts
to 4 miles. With a further decrease in width to 2 miles the strength of
the current increases to about 4 miles an hour, until at Providence, 45 miles
down, several islands block the channel and cause an acceleration of the current
in what are called the Providence rapids. In these rapids the water, though
swift, is quite smooth, and steamers have no difficulty in ascending them.

The country bordering the river below Great Slave lake is low and flat
and the valley is shallow, with banks seldom exceeding 30 feet in height.

‘Below Providence the Mackenzie passes through an expansion known as
Little lake where it receives the water of a fairly large stream from the
north, Horn river, which rises in the rear of Horn mountain. Continuing
westward it remains wide and sluggish as far as a point near Trout river known
as the “Head of the line,” so called because in ascending the river the sluggish
current above permits travellers to discard the tracking line and use oars or
paddles. Yellowknife river and Trout river, streams that are both reported
to head ‘in-large lakes, are passed on the south side. The current increases its
strength at the “Head of the line” and from that point to the mouth of the
Liard, 75 miles, it continues very swift and the width of the stream is reduced
to a little more than half a mile. The banks are here slightly higher and instead
of sand and clay are composed of gravel and sand.

Simpson is situated on an island 2 miles long just below the junction
of the Liard and the Mackenzie. The main channel of the river is here one
mile wide and from this point northward to the Arctic the full width of the
stream is rarely less than this. :

From Simpson to the mouth of Nahanni river, a distance of 75 miles
the Mackenzie maintains its northwesterly direction. Its banks are about 200
feet high, with gravelly or bouldery beaches, and the current runs at an
average rate of 4 miles per hour. Several groups of long low islands occupy
this stretch and the only tributary large enough to be worthy of a name is
Marten river which enters from the southwest 8 miles below Simpson. —

1 Tyrrell, J. W., Dept. of the Interior, Can., 1901, pt. IIT, p. 98. ;
2 Back, Capt. G., “Narrative of Arctic land expendition in 1833-34 and 35.”