952 MINNESOTA BOTANICAL STUDIES. 



graphers as the Northwest Angle. Within American waters are 

 about forty islands, of which the three largest are, in their 

 order, Oak, Garden and Flag island. 



Drainage. — The drainage basin of Lake of the Woods is ap- 

 proximately 36,000 square miles in extent. This is pretty 

 equally divided between Minnesota and Ontario, only an insig- 

 nificant fraction belonging to Manitoba. The basin comprises 

 the country along the Rainy river and its tributaries, with the 

 region bordering upon Rainy lake and its sources. The waters 

 of Lake of the Woods empty into the Winnipeg river over two 

 falls, with rapids between the towns of Rat Portage and Kee- 

 watin, on the Canadian Pacific railway. These towns are situ- 

 ated upon the extreme northern bay of the lake and the falls, 

 divided by Tunnel island, are now being utilized to develop 

 electric power for transmission to a distance. 



General topography. — The mean level above the sea of Lake 

 of the Woods is 1062 feet. Considerable variation — as much as 

 ten feet in some of the bays — between high and low water has 

 been recorded ; but such fluctuations are not common, although 

 a variation of from six to eight feet in level is altogether or- 

 dinary. The remarkable shape of the lake, as may be seen by 

 reference to the accompanying map, gives the wind an unusual 

 opportunity to raise the level on lee shores when it has been 

 blowing continuously for some hours in one direction. A very 

 great variation by seasons also characterizes the volume of the 

 Rainy river. 



As may be noted by further examination of the map, the 

 Lake of the Woods proper separates into two regions, the 

 northern and northeastern island crowded area, sometimes 

 named Clearwater lake on the maps, and the southern and 

 southwestern open, island free area. This latter is called the 

 Traverse by local navigators. The smaller lake, tributary by a 

 short series of rapids to Lake of the Woods, and indicated on 

 the map as Shoal lake, has a somewhat similar massing of 

 islands in the northern portion. The eastern bays of the lake 

 are choked with islands, and they are not absent from the 

 western bays in the northern part, but only a few islands close 

 to shore can be seen in Buffalo or in Muskeg bay to the south- 

 west. The shores of the lake are, for the greater part, low, 

 but some altitudes of 100 feet have been observed. Precipitous 

 cliffs, such as those of some of the international boundary lakes 

 between Rainy lake and Lake Superior, are unusual. Here 



