In terms of size, habitat diversity, and biological productivity, the Mississippi River is one of the world’s major river systems. It is the largest river in North America, flowing 2,340 mi (3,765 km) from its source at Lake Itasca in the Minnesota North Woods, through the midcontinental United States, the Gulf of Mexico Coastal Plain, and the warm temperate climate of the Louisiana Delta. “Mississippi” is an Ojibwa (Chippewa) word meaning great river or gathering of waters—an appropriate name because the river basin, or watershed, extends from the Allegheny Mountains in the eastern United States to the Rocky Mountains, including all or parts of 31 states and 2 Canadian provinces. The river basin measures 1.85 million mi2 (4.76 million km2), covering about 40 percent of the United States and about one-eighth of North America. Of the world’s rivers, the Mississippi River ranks third in watershed area and seventh in average discharge.