The water system provides drinking water for 42 million people and is a defining characteristic of the states and provinces along its borders.

NPR: Governors Meet on Access to Great Lakes

"The idea is that the same thing is true for colors, that there are certain kinds of colors that are characteristic of stuff that's good for us as a species -- clear sky, clear water -- and stuff that's bad for us, like rotting foods, biological waste products, " he said.

CNN: Is 'red' the same to all creatures?