Kamath (P) is a nonprofit association of water users whose interests are adverse to tribal interests in Klamath River Basin water. P filed a series of requests under FOIA seeking access to communications between the Bureau of Indian Affairs and various Indian Tribes regarding the Klamath River Basin. Several documents were turned over, but others were withheld as exempt under work product and deliberative process privileges. These privileges are incorporated under Exemption 5, which exempts from disclosure any inter-agency or intra-agency memos, or letters, which would not be available, by law to a party other than an agency in litigation with the agency (552(b)(2)). P then sued to compel the release of the documents. Seven documents remained at issue. Six of them were prepared by the Tribe or its representative and were submitted at Government behest to the Bureau. The seventh was prepared by the Bureau and given to the lawyers for the Klamath and Yurok Tribes. The court granted the government’s motion for summary judgment and each qualified as an inter-agency or intra-agency communication for purposes of Exemption 5. Each was also covered by deliberative process or the work product privilege. The 9th Circuit reversed; The Tribes had a direct interest, and they could not extend Exemption 5 to shield ex parte communications in contested proceedings between the Tribe and the Department. The Supreme Court granted certiorari.