Somewhat lost amid the flurry of opinions handed down by the United States Supreme Court at the end of the 2010-11 session was its grant of certiori in PPL Montana LLC v. Montana (the link takes you to the SCOTUSblog page for the case, which contains the underlying opinion and the cert documents). PPL Montana, Montana's largest private producer of hydroelectric power, appealed a decision from the Montana Supreme Court that, among other things, required the company to pay rent for its use of Montana rivers. The Montana Supreme Court concluded that the Missouri, Madison, and Clark Fork Rivers were owned by the state because the rivers as a whole were navigable when Montana entered the Union. The company argued, unsuccesfully, that the navigability of a river must be determined "section by section," rather than in the entirety, and that the portions of the rivers that the company uses are not navigable.
The case is seen by many commentators as another opportunity for the U.S. Supreme Court to address the notion of "judicial takings" that it recently addressed in Stop the Beach Renourishment v. Flordia Dept. of Environmental Protection. (Broadly speaking, the question presented in that case was whether a judicial decision can qualify as a "taking" - think eminent domain - that requires the person from whom property is taken to be compensated under the U.S. Constitution.) In Stop the Beach, Chief Justice Roberts and Justices Scalia, Kennedy, and Alito held that there was such a thing as a judicial taking (although no member of the court believed there was a taking in the case itself). Several other justices suggested that they might be pursuaded to join these four in a future decision, but that Stop the Beach was not the right case to do so because there was no taking and thus the court did not need to reach the broader, essentially theoretical, question of whether judicial action could ever amount to a taking. The PPL Montana case may provide the opportunity for at least one of these justices to join the four who are already willing to recognize judicial takings. Stay tuned for more details as the case develops.