What is the largest body of water and the main river found in the boreal Sheild?

Question

What is the largest body of water and the main river found in the boreal Sheild?

Answer 1

Nelson River?

Saint Lawrence River?

Answer 2

The largest "body of water" that lies at least partially on the boreal shield is Lakes Michigan & Huron (they are, indeed, one single body of water).  Given that the St. Lawrence River drains the Great Lakes, it would qualify as a major river.

Answer 3

Balkal lake located in Russia... it is couple killometers deep and very very cold and fresh. The river is Nile