JEFFREY BROWN: Next, a land dispute at the high court with roots in the early 1800s.
And to Gwen Ifill.
GWEN IFILL: Montana's rivers are pristine and iconic, but they are also at the center of a property rights dispute that went all the way to the Supreme Court today.
A lower court ruled that the power company PPL Montana owes the state $53 million in back payments, essentially rent for its use of riverbeds for hydroelectric plants and dams. But who owns the riverbeds, the state, the federal government or private owners?
The answer to that question could have broad impact throughout the American West, as well as the rest of the country.
Marcia Coyle was in the courtroom for today's arguments, and she joins us now.
So, Marcia, this basically started as a challenge for public education funding?
MARCIA COYLE, "The National Law Journal": Right, a group of parents who felt that Montana's educational system was underfunded brought the first lawsuit against the power companies. They ultimately were thrown out of court, and the state stepped in to carry the lawsuit forward.
GWEN IFILL: Why is there any disagreement about who actually owns the land? It seems like the land is always by, I don't know, the government, the people?
MARCIA COYLE: Well, this is really interesting that it's happening more than 100 years after Montana entered the Union.
But it hasn't been litigated much. What happens is, when a territory became a state, the rule was that the United States gave title to the state of the navigable waters in that state. And no -- not -- there hasn't been much litigation over how to define navigable.
There are a couple of Supreme Court decisions. They date to the 1800s. But the justices today really had to struggle to find, what's the right test for what is navigable?
GWEN IFILL: So, why does it matter whether something is navigable? And by navigable, I assume you mean kind of unobstructed, that commerce could happen on this river.
MARCIA COYLE: Right.
Well, if the river is navigable, then the state does have title to the riverbeds and the banks of the river. If it's not navigable, it belongs to the United States. The United States retains title. The power company here has had dams and hydroelectric projects on the Missouri River, the Clark Fork River and Madison River in Wisconsin. Some of those dams are almost 100 years old.
And it was only until this lawsuit began that Montana sort of realized that, hey, we would like to own -- we believe we own the riverbeds underneath these projects.
GWEN IFILL: And, therefore, you owe us for all the money you have been making off of it all this time.
MARCIA COYLE: Exactly. Some states assume they own that. And they have thousands of leases out for uses of their rivers.
But Montana did not for these power projects. The projects had leased -- had arranged leases with the United States and private landowners in order to raise the dams.
GWEN IFILL: So, where do Lewis and Clark come into these arguments?
GWEN IFILL: It seems that they played a role on both sides.
MARCIA COYLE: They did, because the court has to determine whether the rivers were navigable at the time that Montana entered the Union, which was 1889.
And so both sides have been using Lewis and Clark's journals of their expedition up the Missouri River in particular in the early 1800s. The power company claims that the lower court here made a critical error in deciding whether the Missouri River and the other two rivers were navigable, that it focused on the whole river, instead of on sections of the river.
The power plant, for example, has a project on a section of the river that includes the Great Falls. Now, that's a 17-mile stretch that everybody agrees is impossible, and thus not navigable. Lewis and Clark when they arrived at that point had to do a portage. They had to take land around the Great Falls. And they even dispute, both sides, how long that took.
MARCIA COYLE: The power company claims it took 33 days. Montana claims it took much less time than that.
So the power company is saying, you have to look at sections of the river in order to determine what's navigable.
GWEN IFILL: But how do you do that? How would you -- assuming that the power company was able to win this, they're talking about basically slicing up ownership on different chunks of the river.
MARCIA COYLE: Exactly.
And Chief Justice Roberts raised this concern. He said he could see a lot of problems if the courts started drawing lines by chopping up portions of the river. For example, he said, a part of the river that's navigable now may not be navigable in the summer, and it would just create a lot of difficulties.
But the power company claims -- and the United States argued as well here today -- that you have to look at what's a substantial obstacle on the river. And a waterfall, rapids, those are substantial and long-lasting obstacles.
On the other hand, Montana says, no, the rule for over 100 years has been, does the river -- is the river a continuous highway of commerce? So if a portion of the river is obstructed, that doesn't matter. If the portion is still part of a river that acts as a continuous highway of commerce, that river is navigable.
GWEN IFILL: You had two former Bush era solicitors general arguing against each other today.
MARCIA COYLE: We did. And that's unusual, and really good arguments. Paul Clement represented the power company, and Gregory Garre represented the state of Montana. They are among the best Supreme Court advocates in the country.
GWEN IFILL: Did that make any difference in the way the whole argument was received today at the court?
MARCIA COYLE: I don't think in terms of reception.
I think the justices really appreciate good lawyers. And these lawyers had answers for every question. And I think that always helps the justices when they have to reach a final decision.
And there's a lot at state here -- stake here. Sorry. Twenty-six states have filed an amicus brief supporting Montana. And they say they have, again, thousands of leases out for existing uses of their rivers, everything from boat ramps to mineral development. And they worry that if what they believe is the correct rule, what Montana says, look at the whole river, that all that will be jeopardized.
GWEN IFILL: So they're anxious for someone to establish a precedent somewhere in all of this.
MARCIA COYLE: Absolutely.
GWEN IFILL: Marcia Coyle of National Law Journal, thanks so much.
MARCIA COYLE: My pleasure.