This week we’re looking at Lake Michigan, the only one of the Great Lakes that is located entirely within the United States. The lake touches the U.S. states of Wisconsin, Illinois, Indiana, and Michigan. It has a surface area of 22,400 square miles making it the largest lake entirely within one country by surface area, and the fifth largest lake in the world. It is 307 miles long by 118 miles wide with a shoreline 1,640 miles long. The lake’s average depth is 46 fathoms 3 feet (279 ft; 85 m), while its greatest depth is 153 fathoms 5 feet (923 ft; 281 m). It contains 1,180 cubic miles of water.
The lake fluctuates from month to month with the highest lake levels in October and November, and the lowest water levels during the winter months. Lake Michigan, along with the other Great Lakes, is used to supply drinking water to tens of millions of people in bordering areas. In addition to the drinking water supply, Lake Michigan also boasts a healthy sporting and commercial fishing industry, with fish varieties such as lake whitefish, lake trout, yellow perch, panfish, largemouth bass, smallmouth bass, bowfin, and some species of catfish. The lake is also home to a wide range of bird populations, including water birds such as ducks, geese and swans, crows, robins and bald eagles. Predatory birds like hawks and vultures are also prevalent on the lake, due to the wealth of wildlife to feast upon.
Lake Michigan has exclusive claim to the pebble-shaped Petoskey stone. Petoskey stone is a fossilized coral unique to the northern Michigan shores of Lake Michigan.