Plaintiffs William Fletcher, Tara Damron, Richard Longsinger, and Kathryn Redcorn, individual holders of Osage headrights, filed suit against the United States in the Court of Federal Claims (Claims Court) seeking damages resulting from breach of fiduciary duties relating to royalties from the Osage mineral estate. Fletcher v. United States, 151 Fed. Cl. 487 (2020) (Claims Court Decision). Because the Claims Court incorrectly concluded that the plaintiffs had no standing and had failed to identify a source of money-mandating obligation as required under the Tucker Act, we reverse the dismissal of the complaint. We also vacate the Claims Court’s decision on the availability of a damages accounting and the striking of declarations.