In 1930, athlete Fred Newton became the first person to swim the length of the Mississippi River. He began in Minneapolis, planning to take three months to reach New Orleans, though he made it about a month later than scheduled. The then-27-year-old did have some help, though — his brother followed him in a rowboat, carrying supplies and taking notes.

The Mississippi River is generally broken into three sections: the Upper Mississippi, the Middle Mississippi, and the Lower Mississippi. Each has a different environment to flow through. The Upper is marshy with a lot of lakes, the Middle is turbulent and muddy, and the Lower is slow, meandering, and swampy.

It takes a full three months for a single drop of water to travel the entire length of the Mississippi River. The water’s surface speed changes throughout the length of the river, starting at 1.2 miles per hour, which is about half the speed the typical person walks, to about three miles per hour before it empties.

Where the Mississippi River begins in Minnesota, it’s pretty shallow — less than three feet deep. But if you travel toward the end of the river, you will encounter its deepest point, which is right before the Mississippi empties into the Gulf of Mexico. It reaches depths of about 200 feet between Governor Nicholls wharf and Algiers Point in New Orleans.

In 1922, Lake City, Minnesota, native Ralph Samuelson grabbed two wooden boards and a clothing line, hooked himself up to a boat, and invented waterskiing. He was towed by his brother Ben through Lake Pepin in Minnesota, the widest part of the Mississippi River. Once he perfected the stance, he spent 15 years teaching others how to water-ski.

A full 25% of North America’s fish population lives in the Mississippi River. That equates to 260 types at minimum, including bass, carp, bluegill, eel, catfish, sturgeon, and more. In addition to all the fish, the Mississippi River has more than 145 species of reptiles and amphibians and more than 50 mammal species on the Upper Mississippi alone.

Growing up next to the Mississippi River in Hannibal, Missouri, gave Mark Twain (whose real name was Samuel Clemens) inspiration for much of his writing. One of his most famous novels, Adventures of Huckleberry Finn, was set on the river, and Twain himself had a long history on the Mississippi — he worked as a steamboat pilot there before the Civil War.

The Mississippi River runs through 10 states: Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. It mostly flows along the borders between the states, carrying more water than any other river in the United States. Its tributaries reach out to 31 states and two Canadian provinces. The Mississippi is the fourth-longest river in the world.

The Great River Road, beginning in Minnesota and ending in Louisiana, is a collection of state and local roads that trace the path of the Mississippi River through 10 states. It takes about 36 hours to drive the route, with most people completing the entire road trip in four to 10 days. The signs marking the road feature an image of a ship’s wheel.

The Mississippi River runs for about 2,350 miles, heading from northern Minnesota’s Lake Itasca down to the Gulf of Mexico in Louisiana. It’s the second-longest river in the United States. The Mississippi falls just behind the Missouri River, which runs for about 100 miles longer, from the Rocky Mountains in Montana to St. Louis, where it joins up with the Mississippi.