24 B. N. A. BOUNDARY COMMISSION. 
a link in the through route from Lake Superior to Manitoba. The mouth 
of Rainy River is also, and has been from time immemorial, a favourite 
camping place of the natives. At Rat Portage there is a small Hudson’s 
Bay Post, surrounded by a stockade, and trading with Indians hunting 
over a great area of country. 
Former Geological Kxplorers. 
40. The geology of the Lake of the Woods was first discussed by Dr. 
J. J. Bigsby, in a paper which appeared in the seventh volume of the 
Journal of the Geological Society (1852), and gave the results of an exam- 
ination made, I believe, in 1823, during a visit to the lake in his capacity 
as Medical Officer to the Boundary Commission Survey of that date. This 
paper gives a remarkably clear general account of the geology of the re- 
gion, and I must express my obligation to it for several facts incorporated 
in the general map appended to this report. Prof. Keating, associated with 
Major Long, in a United States Government expedition to the sources of 
the St. Peter River and neighbouring country, passed through the Lake 
of the Woods by the Canoe Route in 1823, and gives a few notes on the 
lithological character of the rocks observed. Prof. Hind mentions some 
facts bearing on the geology, in his Reports (1857 and 1858). Prof. Bell, 
of the Canadian Geological Survey, in his Report for 1872, gives a short 
account of the rocks seen during a canoe voyage from Rat Portage 
to North-west Angle, and some conclusions on the general geology.* 
Detail of Observations on Geology.—Laurentian. t 
41. On approaching the Lake of the Woods from the west, by the road 
from Winnipeg, the first rock in place is seen about three miles east of 
Birch Creek Government Station, and consists of Laurentian granitoid 
gneiss. About eleven miles east of the same place, and on the eastern 
margin of the Caribou Muskeg, a large surface of a similar rock is exposed, 
and is seen to be traversed by veins of red felspar. A mile further east, 
another good series of exposures occurs, the rock being a greyish gneiss, 
the lamination of which has a strike of N. 60° E. It is intersected by 
many veins of red felspar running in all directions. About fourteen miles 

*'To Mr. A. L. Russell [am indebted for much information concerning the part of the lake which I 
was unable personally to visit; also for an opportunity of examining specimens collected by him in Lac 
Plat, and assistance in bringing the map up to date by the addition of the results of recent surveys. 
+ The bearings given throughout this chapter are magnetic. The variation at the North-West Angle 
being 11° 17’ East, according to observations by Capt. Anderson, R.E., in October, 1872, 

