Opinion of the Court
Because the existing dusky gopher frog populations were all located in two adjacent counties on the Gulf Coast of Mississippi, local events such as extreme weather or an outbreak of an infectious disease could jeopardize the entire species. Designation of Critical Habitat for Mississippi Gopher Frog, 75 Fed. Reg. 31394 (2010) (proposed 50 CFR Part 17).
To protect against that risk, the Service proposed to designate as unoccupied critical habitat a 1,544-acre site in St. Tammany Parish, Louisiana. The site, dubbed “Unit 1” by the Service, had been home to the last known population of dusky gopher frogs outside of Mississippi. The frog had not been seen in Unit 1 since 1965, and a closed-canopy timber plantation occupied much of the site. But the Service found that the site retained five ephemeral ponds “of remarkable quality,” and determined that an open-canopy forest could be restored on the surrounding uplands “with reasonable effort.” Although the uplands in Unit 1 lacked the open-canopy forests (and, of course, the frogs) necessary for designation as occupied critical habitat, the Service concluded that the site met the statutory definition of unoccupied critical habitat because its rare, high-quality breeding ponds and its distance from existing frog populations made it essential for the conservation of the species. Designation, at 35118, 35124, 35133, 35135.
After issuing its proposal, the Service commissioned a report on the probable economic impact of designating each area, including Unit 1, as critical habitat for the dusky gopher frog. See 16 U. S. C. §1533(b)(2); App. 63. Petitioner Weyerhaeuser Company, a timber company, owns part of Unit 1 and leases the remainder from a group of family landowners. Brief for Petitioner 16. While the critical-habitat designation has no direct effect on the timber operations, St. Tammany Parish is a fast-growing part of the New Orleans metropolitan area, and the land-
