The Supreme Court is entering a $40 million dispute between an energy company and Montana that could turn on the experiences of the Lewis and Clark expedition.
The justices said Monday they will hear an appeal from PPL Montana of a state court decision ordering the company to pay $40 million in rent for placing its hydroelectric dams in riverbeds owned by the state.
The ownership of the waterways turns on whether they were navigable when Montana became a state in 1889. Both the company and the state base part of their argument on the journey of Meriwether Lewis and William Clark more than 200 years ago.
The state says that portions of three rivers that are in dispute have a history of navigation dating back to the expedition and Lewis' description of rivers that run through "such a mountainous country and at the same time are so navigable as they are."
The company points to accounts of the expedition's arduous portages of canoes and supplies around waterfalls to argue that the contested stretches of water were not navigable.
The case will be argued in the court's term that begins in October.
The case is PPL Montana v. Montana, 10-218.