The Osage Nation is a federally recognized tribe. Its headquarters and most of its members are located on the Osage Reservation in Pawhuska, OK. The Osage Tribe Allotment Act of 1906 (Act)1 reserved the Osage Nation's mineral estate to the Osage Tribe and directed that the Tribe's "headright holders"2 receive the estate's royalty revenues (see Appendix 2 for a history of the Osage Nation's mineral estate). The Osage Nation Minerals Council (Council) represents the headright holders.