It may be known as the Nation's River, but here where the Potomac carves its way between Maryland and Virginia, ownership is up for grabs.
A court battle that pits a group of property owners against two small paddling and tubing companies seeks to establish who controls the river, the banks and the mud below. A Washington County circuit judge has pushed the dispute across the water to Loudoun County, Va., saying he lacks jurisdiction.
But it's not clear that Virginia's justice system has standing either. As a result, some water-rights experts say, the case could make its way to the Supreme Court.
Blame King Charles I. Or Lord Baltimore. Or even George Washington. That's how long people have been trying to draw a line in the water.
"To local residents, the Potomac River is shorthand for the boundary between Maryland and Virginia," Circuit Judge M. Kenneth Long Jr. wrote recently. "That simplicity and ease belies the centuries of legal, sometimes actual, fighting between the two states over rights and privileges each have on the Potomac."
The river, the judge concluded, "is a prize worth fighting over."
Potomac Shores Inc., a Frederick entity incorporated in Maryland in 1948, claims it owns 550 acres along and under the river. It alleges that paddlers and tubers are trespassing when they leave the water on the Virginia side near the Route 340 bridge in an area known as Potomac Wayside to wait for shuttle buses to pick them up.
The corporation sent cease-and-desist letters to River and Trail Outfitters and River Riders in 2011 and filed suit a year later when it decided its demands were being ignored. In its legal filings, Potomac Shores hinted at the possibility of licensing agreements to resolve the matter.
But the defendants believe courts have decided that the Potomac belongs to Maryland right up to the low-water mark on the Virginia side. The riverbank on that side is controlled by the National Park Service, with which they have permits to operate.
"When it comes to river navigation, the people's right cannot be infringed upon," said Charles Bailey, the lawyer for River and Trail Outfitters of Knoxville in Frederick County. "Tens of thousands of people come out here and use the river every year. No one can claim to own it."
David Skeen, the lawyer for River Riders of Harpers Ferry, scoffed: "They want my client to pay for a privilege they don't have the right to give."
Late last month, Long declined to reconsider his decision, clearing the way for Potomac Shores to pursue its claim with Maryland's Court of Special Appeals or take up the matter in Virginia.
Requests for an interview with the lawyer representing Potomac Shores were unsuccessful, but Bailey said he expects the case will be appealed.
"I have no indication they will, but if they don't, they have 550 acres that are totally worthless unless they get a ruling in their favor," Bailey said.
Matt Logan, president of Potomac Riverkeeper, an advocacy group that filed a friend of the court brief on behalf of the paddlers' position, calls the disputes "an age-old story." And indeed, it is.
Nearly four centuries ago, King Charles I set the boundaries for Lord Baltimore's colony of Maryland, using the Potomac River's high-water mark as the southern edge. But King James II gave the river to Virginia. In 1776, Virginia's Constitution relinquished claim to the river but retained the right to use it. Maryland rejected that claim.
It took George Washington to work out a compromise, the 1785 Mount Vernon Compact, to settle navigational rights not only on the Potomac but on the Chesapeake Bay.
In 1877, federal arbitrators selected by the two states set the boundary at the low-water mark on the Virginia side, which was approved by Congress. A 1928 boundary survey confirmed the line, as did a 1959 survey.
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."