1. Introducing the Great Lakes

3. The Great Lakes and their connecting channels form the largest fresh surface water system on Earth. –Visible from the moon One of the youngest natural features on the North American continent. Cover more than 94,000 square miles and drain more than twice as much land. Hold an estimated 6 quadrillion gallons of water, about one-fifth of the world's fresh surface water supply and nine-tenths of the U.S. supply.

4. Spread evenly across the contiguous 48 states, the lakes' water would be about 9.5 feet deep. All five of the Great Lakes are among the world's 18 largest lakes by area and volume. The Great Lakes and islands within them have more than 10,000 miles of coastline.

5. The Great Lakes watershed includes part or all of eight U.S. states (Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, Pennsylvania and New York) and the Canadian province of Ontario. Today, more than 33 million people inhabit this drainage basin: more than one-tenth of the population of the United States and one-quarter of the population of Canada.

6. The Great Lakes Watershed

7. Lake Superior is the largest of the Great Lakes in surface area and volume. L. Superior has the largest surface area of any freshwater lake in the world. –The lake stretches 350 miles from west to east and 160 miles north to south. –Its shoreline is nearly 2,800 miles long. L. Superior is also the coldest and deepest of the five Great Lakes. Average depths are close to 500 feet; the deepest point in the lake reaches 1,332 feet.

8. Lake Michigan is the second largest of the Great Lakes by volume The only Great Lake entirely within the United States. Averages 279 feet deep –Reaches 925 feet at its deepest point L. Michigan is approximately 118 miles wide and 307 miles long and boasts more than 1,600 miles of shoreline, including many sandy beaches. –The world's largest freshwater sand dunes line the shores of Lake Michigan.

9. Lake Huron is the third largest of the Great Lakes by volume The shores of Huron extend more than 3,800 miles –the longest shoreline of the Great Lakes, counting the shorelines of its 30,000 islands. –Manitoulin Island in Lake Huron is the largest freshwater island in the world. –characterized by shallow, sandy beaches and the rocky coasts of Georgian Bay. L. Huron is 206 miles wide and approximately 183 miles from north to south.

10. Lake Huron averages a depth of 195 feet and is home to many ship wrecks,. Hydrologically speaking, Lakes Michigan and Huron are actually "one" Great Lake, separated by the Straits of Mackinaw. –The Mackinac Bridge spans the straits, connecting Michigan's upper and lower peninsulas.

12. Lake Erie is the shallowest of the Great Lakes (averaging only 62 feet) and overall the smallest by volume. L. Erie is also exposed to the greatest effects from urbanization and agriculture. L. Erie measures 241 miles wide and 57 miles from north to south, and has 871 miles of shoreline. Because it's not as deep as the other lakes, Erie warms rapidly in the spring and summer, and is frequently the only Great Lake to freeze over in winter.

13. Lake Erie is the warmest and most biologically productive of the Great Lakes. The Lake Erie walleye fishery is widely considered the best in the world.

14. Lake Ontario is similar to Lake Erie in surface area and physical dimensions, but is a much deeper lake, averaging 283 feet. Lake Ontario holds almost four times more water than Lake Erie. L. Ontario ranks fourth among the Great Lakes in maximum depth, but its average depth is second only to Lake Superior.

15. Lake Ontario lies 325 ft (99 m) below Lake Erie, at the base of Niagara Falls. Niagara Falls were always an obstacle to navigation into the upper lakes until the Trent-Severn Waterway, along with the Welland and Erie canals were built to allow ships to pass around this bottleneck.

17. Assignment for Wednesday –Look up the history of the Great Lakes or the United States –Find out the name of the explorer or missionary to first see each of the Great Lakes. –Name the person’s country of origin. –Indicate the year of the discovery.