“Lake Michigan has sort of got a personality,” Paul Florsheim said wryly, as if describing an old friend rather than the center of a legal battle that has consumed the last year of his life. “It changes its moods all the time. I go all throughout the year, even in the bitterest part of winter, because it’s just beautiful down there. You have these ice flows, and they’re sort of like volcanoes, and the waves come crashing through these structures. It’s like another world.”

Florsheim has been walking that world, a stretch of the Lake Michigan shoreline in Shorewood, Wis., a small village north of Milwaukee, for more than 50 years, since his childhood. He walked it with his parents. He walked it when he returned to his hometown in 2008 after 30 years away. He walked it with his dog in the early mornings, before anyone else was out, in every season.

And when the recently retired UW-Milwaukee professor walked the route last year, the Village of Shorewood issued him a $313 trespassing ticket for doing so. Now, he’s one face of a growing trend: America’s public waterfronts are increasingly … less so.

Florsheim’s legal fight is winding its way through the Milwaukee County Circuit Court, on his way, he hopes, to the Wisconsin Supreme Court. Florsheim thinks the stakes are considerably larger than one man’s morning walk. He sees the same dynamic at work in the Texas Supreme Court’s June 19 ruling that handed Elon Musk’s SpaceX effective control over Boca Chica Beach—known locally as “poor man’s beach”—and in the wave of data center projects now competing for access to Great Lakes freshwater.

“If we don’t stand up for what is ours, sort of collectively ours, we’re going to regret it down the road,” he told Fortune.” People don’t want to give up what belongs to them, just as members of the citizenry. And I do think that’s what’s resonating right now.”

Florsheim’s case began when his neighbor—a dentist who built a boathouse on the beach and monitored foot traffic from it—began calling cops on walkers. When Shorewood issued him the ticket, Florsheim’s first instinct was to fight it. When the village lawyer called before the Dec. 2024 trial and encouraged him to settle, warning of mounting court fees, Florsheim declined. When the trial began, it drew a packed courtroom, and the NPR member station story previewing it became the most-read piece in the station’s history, per Florsheim.

He’s well aware about what makes his case unusual. “A water policy professor at UW told me, ‘I’ve been waiting for a case like this my whole life.’ And I said, ‘What do you mean? This must happen all the time.’ She said, ‘No, it doesn’t. People probably get tickets with some regularity for walking on the private part of the beach, but nobody fights them.'” The retired professor, the grandson of the founder of Florsheim Shoes, paused: he had the resources to lead the charge. “The average person would not be doing what I’m doing. I’m retired, so I have the time. Would I be doing this if I was hiring a lawyer? The honest answer is probably no.”

Wisconsin, like most states, recognizes the “Ordinary High Water Mark”—the line where exposed shoreline ends and open water begins—as the boundary of public ownership. But where many states allow the public to cross private beachfront in transit to reach those publicly held waters (also known as “riparian” access) Wisconsin grants landowners exclusive control over that strip of shoreline. You can boat, fish, or swim freely if you’re in the water, but you just can’t set foot on the sand to get there.

The charge rests on Doemel v. Jantz, a 1923 Wisconsin Supreme Court ruling that Florsheim has spent months researching. He said he contacted the archivist at the University of Wisconsin-Oshkosh, which sits on Lake Winnebago where the original dispute originated, finding that it involved a dairy farmer’s right to walk his cattle through the privately owned property to get to the publicly owned water. If his cattle remained in the public water, he was golden; if they crossed that barrier onto sand, not so.

The municipal judge who ruled against him in January wrote a 16-page opinion—extraordinary for a small municipal court—holding that she was bound by Doemel, but that it “probably should be revisited and perhaps overturned.” On June 22, Florsheim’s attorneys filed their response brief with the circuit court, arguing the land he walked is owned by the state of Wisconsin, not his neighbor. “It is decidedly not his land; it is the public’s land,” the brief states. The access to that land, Florsheim argues, doesn’t require a public vote to be protected. “The access to the beach is part of the public trust doctrine, which is baked into the state’s constitution,” he said. “So even though there hasn’t been a vote, there really doesn’t need to be, because it is established.” A hearing is set for August 13.