Why is the Mississippi River Muddy?

To discover first hand why the Mississippi looks so nice and blue up north, and not so nice in Louisiana, we took a trip outside to do a little investigation (thank you Mrs. Foster!). The Mississippi runs through 10 states, so 10 students represented these states with cups of dirt (soil from their state). The rest of the class sat in a crooked line to represent the river. They passed a bucket of clear water down the "river." As it passed each state, it "took" a little of the soil, making the river muddy. When it got to the end, I asked, "So, how does the Mississippi River look when it gets to Louisiana?" Someone shouted, "DIRTY!" :) They'll never forget why the river's nickname is the "Muddy Mississippi."