The maximum depth of Lake Michigan is approximately 925 feet, and the average depth is 279 feet, according to the U.S. Environmental Protection Agency. Lake Michigan is the third largest Great Lake, stretching 321 miles long and 118 miles wide.
Lake Michigan's name is derived from the Algonquin word "michigami," which means "big lake." It was first mapped by French explorers in 1673, and the first French cargo ship sailed its water six years later, transporting furs. Lake Michigan is the only Great Lake located entirely within U.S. territory, and its borders are formed by Michigan, Indiana, Illinois and Wisconsin. Roughly 100 streams connect to Lake Michigan's large drainage basin, which measures 45,500 square miles. At the lake's northern tip, the Straits of Mackinac circulate water to Lake Huron.