The Mississippi River is 3,730 kilometers long. Its source is Lake Itasca, 446 meters above sea level in northwestern Minnesota, USA. It flows from north to south through the Central Great Plains and into the Gulf of Mexico. The longest tributary of the Mississippi River is the Missouri River, which is about 4,000 kilometers long. It originates from the eastern slope of the Rocky Mountains near Yellowstone Park in Montana, flows through the semi-arid Great Plains, and merges into the Mississippi River in St. Louis, Missouri. The total length of the Missouri-Mississippi River is 6,021 kilometers, ranking fourth in the world, after the Nile River, the Amazon River, and the Yangtze River.

The flow of the Mississippi River is about 16,800 cubic meters per second, which is slightly more than half of that of the Yangtze River. It ranks about tenth in the world. Our mother river, the Yangtze River, ranks fourth in the world after the Amazon River, the Congo River, and the Orinoco River.