Here's the short version: The Supreme Court of the United States ruled some time ago that the Black Hills were taken from the Lakota (Sioux) in violation of treaties they had with the U.S. Government.
But the court also ruled that tribal members could receive money as the only available form of damage settlement - the Hills themselves would not be given back.
Many Lakota leaders have refused to take the cash and continue to assert their claim for the Hills, which they consider sacred.
But there are divisions among the L/N/Dakota tribes, as some see the monetary settlement as the right way forward.
The Rapid City Journal has a couple of articles this week, here and here.
Be sure to read the comments with each - you will see the amazing diversity of opinions and approaches.