The boundary settled, Maryland and Virginia got into a legal spat over the right to withdraw water from the Potomac that in 2003 ended up before the Supreme Court. Then-Chief Justice William H. Rehnquist's decision allowed Virginia to build a pipeline into the river to supply growing residential areas.
"You would think in 2003 and 2013 there wouldn't be any issues left to decide, but every couple of years, there's a unique border dispute because they didn't think of something," said Adam Van Grack, a Montgomery County lawyer who specializes in outdoor recreation legal issues.
In this case, Potomac Shores is arguing that the permanent boundary should be the low-water mark set by the arbitrators in 1877, not the low-water mark of today. It based its claim on a 1980 Supreme Court ruling in a border spat involving Ohio and Kentucky and the Ohio River.
Given how the Potomac meanders, that could mean a difference of a mile in some spots along the river, Van Grack said.
"We're not just talking about paddlers and fishermen. We're talking about people who have built waterfront homes. We're talking about Donald Trump's golf course," he said. "The ramifications of what Potomac Shores is asking for is huge. It could involve billions of dollars' worth of property."
Because the legal argument involves conflicting Supreme Court decisions over decades, it might eventually find its way back there.
"We like to think of the Potomac as something that draws us together," Logan said. "We recreate on it. We draw water from it, but it is very much a political border and people are going to be poking at it. You have these issues you wish would go away. But they won't."