Is there a way to plan a course using the river systems on Google Earth?

I am trying to plan a trip from Winnipeg, Manitoba, Canada to Trout Lake, Ontario, Canda, though am limited in understanding Google Earths capabilities, so wonder if anyone else has used google earth in a different way to plan a trip using something else other then roads, town to town.

On the top toolbar of Google Earth you will find place marks and the path feature. You can set and name way-points with the place mark feature and connect them with the path feature. There is also a way to save this layout.