PREHISTORIC ABORIGINES OF MINNESOTA 211 



dominion included the boundary waters not farther west than Kainy 

 Lake, but continued unbroken to Hudson Bay. 3 



A few other general considerations ought to be stated at this point 

 in order to prepare for the discussion of the topic in hand. These 

 are: 



1. During the prevalence of the last ice-epoch the state of Min- 

 nesota was covered with ice, and all previous inhabitants, whether fauna 

 or flora, were driven southward to more congenial climes. 



2. This condition ended between seven and eight thousand years 

 ago. It is not necessary here to rehearse the investigations on which 

 that result is based. 



3. Between the ice-fields and the habitable portions of the continent 

 lying to the south was a belt of country, the width of which varied 

 according to the longitude and according to the topography, which was 

 uninhabitable by reason of the severity of the climate. This unin- 

 habitable belt may be compared to a belt in northeastern and northern 

 Canada at the present time which is uninhabitable for the same reason. 

 It was wider, however, than the northern Canadian belt, and less 

 ameliorated along the banks of the rivers. Their waters drained from 

 the northern ice fields, whereas the Canadian rivers carry waters from 

 southern and more temperate latitudes. But like the Canadian belt it 

 was wider toward the west. The ice-margin and the accompanying 

 severity of climate crossed the country from southeast to northwest. 

 The prehistoric isothermals, same as the present, passed northwest- 

 wardly. 



4. Hence the habitable portions of the United States, until seven or 

 eight thousand years ago when the ice began its retreat, were along the 

 Atlantic seaboard south of New Jersey, a belt along the coast of the 

 Gulf of Mexico, a large interior area without ascertainable limits, and 

 the Pacific coast west of the Sierra Nevada. 



5. So far as Minnesota is concerned, and the same is true of much 

 of the northern United States, it seems to be necessary, therefore, to 

 confine all investigation of aboriginal migration to an antiquity not 

 greater than seven or eight thousand years. 



6. For Minnesota it is necessary to make a still further restriction, 

 for it was the ice-margin itself that retired seven or eight thousand 



3 Powell's map of linguistic stocks accompanying the seventh annual report 

 of the Bureau of Ethnology, 1885-6, is quite incorrect for Minnesota. It gives 

 by far too much area to the Algonquian. The boundary as shown by his map 

 would be more applicable in the eighteenth century, after the inroads of the 

 Ojibwa upon the Dakota had won a large part of the state. As it should be 

 drawn from the earliest known habitats of the aborigines, it should start from 

 the St. Croix River not far from the eastern side of Pine County, run thence 

 northwardly to near the east end of Rainy Lake, thence northward and north- 

 westward so as to leave Lake of the Woods to the Assiniboin, but to the south- 

 ward of Lake Winnipeg and thence northwestwardly indefinitely to the valley 

 of the Saskatchewan. 



