III.—On Some Changes of Level during the Glacial Period and their Supposed Cause

Abstract

At the close of the Glacial Period in North America the basin of the Red River was occupied by a large lake which has received the name of Lake Agassiz. It extended from what is now Lake Winnipeg southward for some hundreds of miles to the watershed of the Minnesota River. The bottom of this old lake now forms an extensive level plain famous for its fertility and the fine crops of wheat it produces.