Weyerhaeuser Co. v. U.S. Fish & Wildlife Service, 139 S. Ct. 361 (U.S. 2018)
Weyerhaeuser Co. v.
1) Must an area be "habitat" before it can be designated as "critical habitat" under the ESA? 2) Is the Fish and Wildlife Service's decision not to exclude an area from a critical-habitat designation under ESA §4(b)(2) judicially reviewable under the APA?
Under the Endangered Species Act, only "habitat" for an endangered species is eligible for designation as "critical habitat" (because "critical habitat" is a subset of "habitat"). Furthermore, the Fish and Wildlife Service's decision not to exclude an area from a critical-habitat designation pursuant to ESA §4(b)(2)—which requires the agency to consider economic and other relevant impacts and to weigh the benefits of exclusion against inclusion (subject to the limitation that exclusion may not result in extinction)—is subject to judicial review under the Administrative Procedure Act and is not categorically committed to agency discretion by law. On review, such decisions are evaluated under the APA's arbitrary-and-capricious standard.
The Supreme Court unanimously vacated and remanded. It held: (1) An area must be "habitat" for the species before it can be designated as "critical habitat." The Fifth Circuit erred by upholding the designation without determining whether Unit 1 qualified as "habitat." (2) The Fish and Wildlife Service's decision not to exclude Unit 1 from the critical-habitat designation under ESA §4(b)(2) is judicially reviewable under the APA.
For statutory interpretation, the case exemplifies textual and structural reasoning: a statutory subset ("critical habitat") cannot exceed its superset ("habitat"). This limits agencies' ability to stretch statutory terms beyond their ordinary and structural bounds. For administrative law, the case reaffirms a presumption of judicial review and clarifies that ESA §4(b)(2) decisions are reviewable for arbitrariness—important for regulated entities contesting agency cost-benefit judgments and impact analyses. Practically, Weyerhaeuser impacts critical-habitat designations nationwide by introducing a threshold "habitat" inquiry for unoccupied areas and requiring reasoned explanation when the agency declines to exclude land after considering economic and other impacts. The decision influenced subsequent agency rulemaking and litigation strategy, and it is frequently studied for its approach to limits on agency discretion, property-rights implications, and the ESA's balance between species conservation and economic considerations.