a huge river that forms the western border of Illinois, separating Illinois from Iowa and Missouri. (Label it on the map in two places.)
The Mississippi River, derived from the old Ojibwe word misi-ziibi meaning 'great river' (gichi-ziibi 'big river' at its headwaters), is the second-longest named river in North America, with a length of 2320 miles (3733 km) from Lake Itasca to Gulf of Mexico. The longest named river in North America is its tributary, the Missouri River, with a length of 2341 miles (3767 km) from the confluence of the Jefferson, Madison, and Gallatin to the Mississippi River. Taken together, the Jefferson, Missouri, and Mississippi form the largest river system in North America.
The Mississippi River is a tributary of the Ottawa River in eastern Ontario in Canada. It is 169 km (100 mi) in length from its source in Upper Mazinaw Lake, has a drainage area of 3750 km², and has a mean discharge of 40 m³/s (source: Atlas of Canada). It rises east of the Kawartha lakes and flows northeast through Crotch, Dalhousie, and Mississippi Lakes, past Carleton Place, through the municipality of Mississippi Mills and the town of Almonte, then north to join the Ottawa River just east of Arnprior.
