11 
are full of rapids, which are composed almost entirely of granite boulders 
of glacial origin. The rivers are further obstructed by beaver dams and 
log jams, both of which are very numerous. 
There appear to be certain well-defined soil types in the Alberta plateau 
district. Present knowledge permits only their division into those with a 
preponderance of sand and gravel, and heavier ones with a large admixture 
of clay. These types appear to occupy rather definite areas, the heavy 
soils being found mainly in two regions. The first is a strip of country lying 
between the Pine Lake-Lane Lake district and the area about Flatgrass lake, 
which is near Little Buffalo river on the summer trail between Sucker creek 
and Fort Smith (15) . The second is a band of country west of Jackfish river, 
south of Jackfish lake, and along the base of Caribou mountains. It is 
rather level, with a gentle slope awmy from the mountains. Both of these 
areas of clay soils have many dry watercourses in them. A hole made by 
the writer in a prairie opening near the base of Caribou mountains showed 
a sandy loam to a depth of 24 inches. Below this is a layer about 13 
inches thick in which there is almost pure sand erossbeddcd with clay. 
Frost was struck at 37 inches on June 26. Boulders and gravel are com- 
pletely absent, and where creeks from the mountains have cut deep ravines 
the only larger materials are those brought down by the streams them- 
selves. 
The morainic hills are notable for the large amount of sand and rounded 
boulders, forming extremely dry soils. Any representative of Alberta 
plateau that may occur between Peace river and Birch mountain has not yet 
been examined. The contour map of northern Alberta shows no indication 
of it except on the northern slope of the mountain (67). 
Between the Alberta plateau escarpment and the present lowlands of 
Slave river is a plain that stands at about the 800-foot contour line. The 
northern and southern extensions of it are not well defined, but it is known 
along Little Buffalo river in the latitude of Salt River settlement, and 
extends southeastward well beyond the latitude of the Government Hay 
Camp. The inadequate descriptions of the country farther northward seem 
to indicate that there are representatives of it beyond the Little Buffalo. 
The small prairie at Peace point, on Peace river, is probably a southern 
extension, but its occurrence south of the Peace is uncertain. The plain 
is nearly level, except for some gently rolling areas and a few' morainic hills 
or ridges. Drainage is by the streams above described as flowing from far 
back in Alberta plateau, and by such smaller ones as Salt and Darrough 
creeks in the southern sections. 
Over large areas there are poorly drained, clayey soils, wfith many 
shallow ponds on the surface. Outwash from brine springs at the base of 
the escarpment to the west has left a thin deposit of salt in many of the 
depressions, and caused most of the streams to be brackish. The section 
southwest of Fort Smith has long been known as the Salt Plain, and the 
nearby escarpment as Salt mountain. Most of the early travellers ascended 
Salt river from the Slave to procure supplies of salt at the springs. 
The present level of Athabaska, Claire, and other, smaller lakes in the 
vicinity is about 700 feet above the sea, and most of the lowland bordering 
them in the park area stands only a few’ feet above this. Extensions of the 
lowlands reach dow r n Slave river nearly to Fort Smith, up Peace river nearly 
