A word about the water color of Tahquamenon Falls...

The amber color of the water is not rust nor is it muddiness. It is
caused by tannin leached from the Cedar, Spruce and Hemlock in the
swamps drained by the river. The extremely soft water churned by the
action of the falls causes the extensive amounts of foam which has
been the trademark of theTahquamenon since the days of the voyageurs.

Reference: http://www.exploringthenorth.com/tahqua/tahqua.html