In 2001, the Fish and Wildlife Service listed the dusky gopher frog as an endangered species, under the Endangered Species Act of 1973, 16 U.S.C. 1533(a)(1), which required the Service to designate the frog's “critical habitat.” The Service proposed designating a site in St. Tammany Parish, Louisiana (Unit 1). The frog had once lived in Unit 1, but the land had long been used as a commercial timber plantation; no frogs had been spotted there for decades. The Service concluded that Unit 1 met the statutory definition of unoccupied critical habitat because of its rare, high-quality breeding ponds and distance from existing frog populations. The Service commissioned a report, which found that designation might bar future development, depriving the owners of up to $33.9 million, but concluded that the potential costs were not disproportionate to the conservation benefits and designated Unit 1 as critical habitat. The owners sued, contending that the closed-canopy timber plantation on Unit 1 could not be critical habitat for the frog, which lives in open-canopy forests. The district court and Fifth Circuit affirmed.
The Supreme Court vacated. The decision not to exclude an area from critical habitat is subject to judicial review. An area is eligible for designation as critical habitat only if it is habitat for the species. Section 1533(a)(3)(A)(i), the sole source of authority for critical-habit designations, states that when the Secretary lists a species as endangered he must also “designate any habitat of such species which is then considered to be critical habitat.” Whether the frog could survive in Unit 1; whether habitat can include areas where the species could not currently survive; and whether the assessment of the costs and benefits of designation and resulting decision were arbitrary, capricious, or an abuse of discretion, must be addressed on remand.