Ever wondered about the name of these Osage Nation casinos in Oklahoma?

Here's the answer from the best-selling book "Killers Of The Flower Moon" by David Grann (the Martin Scorsese film version will be in theaters next month)...

During the 1910s and 1920s, some of America's wealthiest oil barons (men like J. Paul Getty, Harry Sinclair, Frank Phillips, Bill Skelly and others) would travel in their luxurious private railroad cars to Oklahoma to attend the four-times-a-year auctions of Osage Nation oil leases held by the U.S. Interior Department.

According to Grann, "In good weather, the auctions were held outdoors, on a hilltop in Pawhuska, in the shade of a large tree called the Million Dollar Elm. Spectators would come from miles away."

Mystery solved!