All rivers are connected. The Nile, Euphrates, Amazon, Danube, Yangtze, Amazon, that little millstream lazying through town—they all flow to the same deep blue sea. And there’s some comfort in knowing, if you live by a river, that the wide world lies just downstream.

I happen to live by the Chippewa River, which heads in small lakes and swamps in far northeastern Wisconsin not far from Lake Superior then flows in the opposite direction, diagonally across the state, and passes within a block of my house on its way to the Mississippi and the Gulf of Mexico and so forth. A river system is one of those vague territories, like a voting district, that we belong to without having to think about it unless there’s a flood or someone drowns. But I think about the Chippewa once a day, usually on my way to work, because it runs through the middle of the campus where I teach, dividing Fine Arts from Science and the Humanities the way a dark fissure separates hemispheres of the brain. A footbridge spans the divide.

When the weather turns summery, I’ll stand at mid-span and watch students launch themselves down the river on brightly colored air mattresses and inner tubes. Buoyed upon their own breath, they link arms and float face-up beneath the footbridge toward New Orleans. I envy their journey, the spontaneity and pointlessness of it. They are adrift between college and whatever comes next—a job, marriage, payments on their student debt. The flotilla slides slowly past the Fine Arts building, a tanning salon, and a Mexican restaurant If the students kept going they might reach the Mississippi in a few days and the Gulf of Mexico by summer’s end. But they never do. A quarter-mile into the voyage, they call it quits and wade ashore at the public boat landing. Shouldering their inflatable white shark or pink flamingo, they hotfoot it up the city bike path to the footbridge, back to where they started, and re-launch while the sun still shines. For the students, the Chippewa is a Round River.

The idea of a Round River goes back at least to the Okeanos of ancient Greece, a great freshwater stream that encircled the earth and flowed back on itself. The myth was an early take on the hydrological cycle an explanation of why rivers flow continuously to the ocean yet never run dry. “All the rivers run unto the sea,” says Ecclesiastes, “yet the sea is not full; unto the place from whence the rivers come, thither they return again.” The North Woods has its own version of the myth in a Paul Bunyan tall tale. One spring, the big lumberjack hops aboard a log raft and heads for the nearest sawmill. Three days later the river, high with meltwater, shoots him past a logging camp that looks suspiciously like Bunyan’s own. Three more days pass and another camp, identical to the first, heaves into view. He keeps going. Not until the third pass does the big galoot recognize his own red long johns flying from the flagpole and realize he’s riding the Round River. That’s the whole story. It’s one of those elaborate jokes that works on an order of three, repeating the same details over again until the situation becomes clear to everyone but our dimwitted hero. There’s no moral, no discernable theme except the obvious: to know where you are in the world it helps to remember where you’ve been.

In the 1940s, Aldo Leopold resurrected Paul Bunyan’s river for an essay that begins: “One of the marvels of early Wisconsin was the Round River, a river that flowed into itself, and thus sped around and around in a never-ending circuit.” Writers are always using rivers as metaphors for one thing or another, and Leopold was no exception. When he wrote, “Wisconsin not only had a round river, Wisconsin is one,” he wasn’t referring to a body of water but the flow of energy from soil to plants to animals to people. Leopold’s “Round River” is an ecological parable, a metaphor for the natural world being interconnected, a closed system, and what goes around inevitably comes around. It’s a fine essay but also a bit of a let-down. The first time I read it, I was terribly disappointed when the title river dried up after page one because a Round River is a beguiling idea. It’s a very Zen idea: start here, paddle there, end up where you began. It’s an idea that can send you scrambling for a map.

John Hildebrand is the author of five books including, most recently, The Long Way Round: Through the Heartland by River from which this excerpt is taken and reprinted with permission of the author.  More by and about John here.