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Flowing over rapids and falls, the Mississippi River drops nearly 700 feet between its headwaters at Lake Itasca and the Twin Cities (Minneapolis and Saint Paul).
It keeps dropping until it reaches the Gulf of Mexico. The river also gets wider as it flows south. Its water level keeps changing, too. This makes it hard to keep the river safe for navigation. It also makes it hard to keep the shores safe for people to live there. But over the years, engineers have built dams, levees, and locks. These devices control the mighty Mississippi.
