Perils of rocky lakes

When the vast ice sheets that covered the Laurentian Shield melted in Canada 10,000 to 12,000 years ago, they left an incredible system of rivers and natural lakes. Examine a provincial map of Saskatchewan or Manitoba, and you will see the striations that look as if a giant hand rubbed the land and caused the patterns of lakes to lay out the way they are.

By: Bernie Kuntz, The Jamestown Sun