United States Fish and Wildlife Serv. v. Sierra Club, Inc., 592 U.S. 261

EPA proposed a 2011 rule regulating cooling-water intake structures; under the Endangered Species Act (ESA) EPA had to consult with the Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS) ("the Services").
Services' staff completed draft biological opinions in Dec. 2013 concluding the 2013 proposal would likely jeopardize certain species and identified reasonable and prudent alternatives.
Services decisionmakers did not approve or transmit those drafts to EPA; they shelved the drafts and extended consultation while EPA revised the proposal.
In March 2014 EPA submitted a substantially revised proposal; the Services issued a joint final "no jeopardy" biological opinion and EPA issued its final rule that day.
Sierra Club sought the withheld 2013 draft biological opinions under FOIA; the Services claimed Exemption 5 (deliberative process privilege); the Ninth Circuit held the drafts were not privileged because they reflected the Services’ final view on the 2013 proposal.
The Supreme Court reversed, holding the withheld draft biological opinions were predecisional and deliberative and thus protected by the deliberative process privilege under FOIA Exemption 5.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether FOIA Exemption 5 protects in-house draft biological opinions that were the agencies’ last-documented views about a proposed rule	Sierra Club: drafts were the Services’ settled view on the 2013 proposal and had "operative" effect (EPA changed course), so they are final and not exempt	Services: drafts were predecisional/deliberative; decisionmakers never adopted or sent them to EPA, so they are privileged	The Court held the drafts are predecisional and deliberative and protected by Exemption 5; label "draft" plus the administrative context showed they were not treated as the Services’ final decision
Whether the practical "operative effect" (i.e., causing the action agency to change course) converts a draft into a non‑privileged final agency decision	Sierra Club: practical effects (EPA revised the rule) show the drafts had finality and must be disclosed	Services: finality depends on whether the agency treated the document as its final view and whether it produced legal consequences; practical effects alone are insufficient	The Court rejected an effects-based test; finality is functional and depends on agency treatment and legal consequences, not merely on practical influence

NLRB v. Sears, Roebuck & Co., [citation="421 U.S. 132"] (establishes the deliberative process privilege and the predecisional/deliberative distinction)
Renegotiation Bd. v. Grumman Aircraft Eng'g Corp., [citation="421 U.S. 168"] (explains that a document is non‑privileged if it reflects the agency's settled position with "real operative effect")
Department of Interior v. Klamath Water Users Protective Assn., [citation="532 U.S. 1"] (discusses Exemption 5 privileges and limits where interagency materials are shared with third parties)
Bennett v. Spear, [citation="520 U.S. 154"] (describes when biological opinions produce legal consequences and the significance of "operative effect" in that context)
EPA v. Mink, [citation="410 U.S. 73"] (articulates the need to protect candid internal communications so agencies are not forced to operate in a "fishbowl")