So large they are visible even from the moon, the Great Lakes of Superior, Michigan, Huron, Erie, and Ontario, and their connecting channels, form the largest fresh surface water system on earth. Covering more than 94,000 square miles, these freshwater seas, with an estimated six quadrillion gallons of water, hold nine-tenths of the U.S. fresh surface water supply and nearly one-fifth of the world’s.

In spite of its size, the eco-system of the Great Lakes is varied and fragile. The 3,288 miles of coastline encompasses huge forests, wilderness expanses and agricultural lands. The world’s largest freshwater dunes are found here as well. Biologically diverse, there are more than 180 species of fish alone native to the Great Lakes along with massive bird populations and furbearing animals too numerous to mention. The number of research and educational organizations dedicated to collecting knowledge on this vast and fascinating region range in the hundreds. For more information go to: www.great-lakes.net/lakes or www.glerl.noaa.gov/.