Osage Nation v. Irby, No. 09-5050, concerned an action by the Osage Nation seeking a declaratory judgment that the Nation's reservation, which comprised all of Osage County, Oklahoma, had not been disestablished and remained Indian country within the meaning of 18 U.S.C. section 1151.
As the court of appeals wrote: "The pivotal issue in this case is whether the Nation's reservation has been disestablished, not Oklahoma's tax policies. The district court held that the Osage reservation had been disestablished; that tribal members who work and live on non-trust/non-restricted land in Osage County are not exempt from state income tax; and that "[t]he Osage have not sought to reestablish their claimed reservation or to challenge [Oklahoma's] taxation until recently," and Oklahoma's longstanding reliance counsels against now establishing Osage County as a reservation."
The court of appeals affirmed summary judgment for defendants, holding that 1) the legislative history and the negotiation process made clear that all the parties at the table understood that the Osage reservation would be disestablished by the Osage Allotment Act, and uncontested facts in the record provided further evidence of a contemporaneous understanding that the reservation had been dissolved; and 2) after enactment, federal officials responsible for the Osage lands repeatedly referred to the area as a "former reservation" under state jurisdiction.