
. five north of the line, where the watershed was again crossed, it preserves © 




B. N. A. BOUNDARY COMMISSION. 
vallies, but consisting of broken tumultuous hills of drift material. 
has a width of over twenty miles on the forty-ninth parallel, anda he 
of about 2,200 feet, and is very definite; but widens when followed to th 
north-west, and becomes more diffuse, and where crossed by the old 
Trader’s Road to Woody Mountain, the tributaries of the Souris Rive 
are found rising within it, and the line of watershed leaving it and fal ng si: 
back somewhat further to the south, so that at Woody Mountain settle- : zat 
ment in longitude 106° 30’, the primary watershed lies only from fifteen — ‘i 
to twenty miles north of the forty-ninth parallel. It is necessary to oe 
specify the primary watershed, as it would appear that most of the small i Ay 
streams now running northward in this region, are intercepted by the 
mounds and ridges of drift material, and caught in saline lakes and be hs 
ponds. Many of them may, however, still find their way to the Saskat- 
chewan in seasons of flood. ' , a 
13. The watershed near Woody Mountain is a narrow flat-topped 
plateau composed of Lignite Tertiary strata, irregular in outline, but 
with a general east and west course, and furrowed on either side by the 
vallies of streams which ramify in it, and which, were denudation advan- 
ced a little further, might inosculate. The height of the water-shed is 
here about 3,200 feet. Fifty miles west of Woody Mountain, and twenty- 












most of the characters just indicated, but has been still more extensively 
reduced by denudation, and has a height of only about 3,000 feet. West 
of this point it trends northward, and is again found in the Cyprés Hills, 
forty miles north of the Line in longitude 110° 30’, where it still appears 
to follow a ridge of Lignite Tertiary deposits, now but a scanty remnant — 
of that once extensive formation, as the streams on either side soon 
debouch on plains of Cretaceous strata, from which the Tertiary has been 
removed by their action. West of the Cyprés Hills the watershed again 
trends southward and crosses the line about thirty miles from the base of — 
the Rocky Mountains for the last time. It here separates the waters of 
the St. Mary, a tributary of the Belly River, from those of one of the 
upper branches of the Milk River, and is scarcely indicated by any 
physical feature, though so important hydrographically. The valley of — 
the tributary of the Milk River and that of the St. Mary River, are deep, 
and the streams are found crossing the Line nearly parallel in a north- 
eastward direction, the Milk River subsequently bending eastward and 
southward, and recrossing the Line twenty miles east of the Sweet-grass 
Hiills. The lower part of the watershed region between them is 
