Legal Sidebari

U.S. District Court Vacates Gray Wolf
Delisting Rule
February 18, 2022
On February 10, 2022, a district court vacated and remanded the U.S. Fish and Wildlife Service’s
(FWS’s) rule (the “delisting rule”) that delisted—that is, removed from the list of endangered and
threatened species—certain gray wolf “entities.” The U.S. District Court for the Northern District of
California held that the rule violated the Endangered Species Act (ESA) and the Administrative Procedure
Act (APA) in a number of ways. For example, the court concluded that FWS could not delist an entity
solely because it determined the listed entity no longer met the definition of a species under the ESA and
that FWS must instead apply the ESA’s explicit standards for delisting. The court also determined that
FWS had not offered a reasonable construction of the phrase significant portion of its range, which
appears in the ESA’s definitions of endangered species and threatened species. This is not the first time a
court has invalidated FWS’s interpretation of this phrase; in 2018, a court vacated FWS’s 2014 joint
policy with the National Marine Fisheries Service (NMFS) interpreting the phrase.
The court’s decision to vacate the delisting rule renders it void and effectively reinstates the listing status
that each gray wolf entity had before that rule was promulgated. The gray wolf therefore is again listed as
threatened in Minnesota and endangered elsewhere in the lower 48 states, except for the Northern Rocky
Mountain distinct population segment (DPS), which had been delisted by prior actions. Vacating the
delisting rule does not affect the listing status of the Northern Rocky Mountain DPS. The court’s decision
may also affect FWS’s decisions on two pending petitions related to listing gray wolf DPSs.
This Sidebar discusses the history of rules relating to gray wolves under the ESA, the court’s recent
decision, and next steps for FWS.
Listing History of the Gray Wolf Under the Endangered Species Act
The gray wolf was first listed under the ESA’s predecessor statute in 1967. In 1973, Congress enacted the
ESA, which requires FWS to list a species as endangered if it determines that the species is “in danger of
extinction throughout all or a significant portion of its range” and to list a species as threatened if it
determines the species is likely to become endangered “within the foreseeable future throughout all or a
significant portion of its range.” The ESA requires FWS to determine whether a species meets these
definitions by analyzing five factors describing potential threats to the species. Listing a species triggers
various requirements and protections under the ESA. The ESA does not specify a delisting process or
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separate criteria for removing a species from the list of endangered and threatened species. Instead,
species are delisted based on the same criteria used for listing: (1) the definitions of endangered species
and threatened species and (2) the five factors describing potential types of threats to species. Other CRS
products provide a high-level overview and an in-depth discussion of the ESA.
In March 1978, FWS listed the gray wolf in Minnesota as threatened and the gray wolf elsewhere in the
lower 48 states as endangered. At that time, the ESA defined species to include “any subspecies of fish or
wildlife or plants and any other group of fish or wildlife of the same species or smaller taxa in common
spatial arrangement that interbreed when mature.” The definition of species was amended in November
1978 to include “any subspecies of fish or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreed when mature.” The ESA does not define distinct
population segment; FWS and NMFS have issued a joint policy interpreting this term.
Since 2003, FWS has issued a number of rules designating DPSs of gray wolves and downlisting or
delisting the DPSs. These rules have generally been overturned by courts. After multiple rules delisting
the Northern Rocky Mountain DPS were vacated, in 2011 Congress directed FWS to reinstate a rule
delisting the gray wolf in the Northern Rocky Mountains other than Wyoming. FWS then delisted the
gray wolf in Wyoming in 2012. After the U.S. District Court for the District of Columbia vacated the rule
delisting the gray wolf in Wyoming in 2014, the U.S. Court of Appeals for the District of Columbia (D.C.
Circuit) reinstated the rule in 2017. Beginning in 2017, therefore, the gray wolf in the lower 48 states was
divided into four separate groups for ESA purposes: (1) the Northern Rocky Mountain DPS was not
listed; (2) gray wolves in Minnesota were listed as threatened; (3) the Mexican gray wolf subspecies in
Arizona and New Mexico was listed as endangered beginning in 2015; and (4) gray wolves in all other
areas of the lower 48 states were listed as endangered. This CRS report provides a more detailed history
of FWS’s listing and delisting decisions related to the gray wolf and associated court decisions.
FWS Delists the Remaining Listed Gray Wolf Entities
On November 3, 2020, FWS issued a final rule delisting the gray wolf listed entities except for the
Mexican wolf, which remained listed as endangered. In the final rule, FWS concluded that the two listed
entities—that is, (1) gray wolves in Minnesota and (2) gray wolves in the lower 48 states outside
Minnesota and the Northern Rocky Mountain DPS—are not species as defined by the ESA (as revised in
1978 to include DPSs). FWS observed that neither listed entity encompassed the entire taxonomic species
or any subspecies of gray wolf and accordingly could be listed only if they met the Services’ criteria for a
DPS. FWS then concluded that neither listed entity qualified as a DPS because neither was discrete from
other populations. FWS determined that the Minnesota wolves were not discrete from the remainder of
the western Great Lakes population and that the entity listed as endangered was not discrete from either
the Minnesota wolves or the Northern Rocky Mountain DPS wolves. FWS concluded that neither listed
entity could remain listed as a species.
Having determined that the existing listed entities did not qualify as species, FWS assessed the status of
various gray wolf groups to determine whether any of them were threatened or endangered species. FWS
assessed the status of each of the two listed entities on their own, as well as the status of those entities
combined (i.e., gray wolves in the lower 48 states outside the Northern Rocky Mountain DPS). Finally,
FWS assessed the status of gray wolves in the lower 48 states (i.e., the two listed entities plus the
Northern Rocky Mountain DPS). FWS concluded that none of those various combinations of the gray
wolf listed entities qualified as endangered species or threatened species under the act. Based on those
determinations, FWS delisted the gray wolf entities.

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Litigation Challenging the Final Rule
In January 2021, WildEarth Guardians, Defenders of Wildlife, and the Natural Resources Defense
Council each filed lawsuits against the Department of the Interior and FWS alleging that the delisting rule
violated the ESA and the APA. On July 16, 2021, the plaintiffs filed a joint motion for summary
judgment. On February 20, 2022, the court granted the motion in part and vacated and remanded the rule
to FWS. In its decision, the court held that FWS had violated the ESA and APA in multiple ways.
First, the court determined that FWS could not delist an entity solely because the listed entity did not meet
the statutory definition of a species. It concluded that the 1978 amendment changing the act’s definition
of species was not intended to lessen protections for species that had been validly listed based on the prior
definition and that upholding the rule on that basis would “amount to an impermissible ‘backdoor route to
the de facto delisting of already-listed species.’” To reach its conclusion, the court relied on a D.C. Circuit
opinion vacating a FWS rule that had first designated and delisted a Western Great Lakes DPS and then
delisted the remnant by concluding that it did not qualify as a species. Finding that decision persuasive,
the district court concluded that allowing FWS to delist gray wolf entities for not qualifying as species
under the current definition would amount to a “statutory dodge” that removed federal protections without
accounting for the ESA’s standards for delisting.
Second, the court concluded that FWS had failed to consider adequately threats to the gray wolf in the
lower 48 states outside the core populations in the western Great Lakes and northern Rocky Mountains. It
determined that FWS had attempted to avoid assessing threats to gray wolves outside the core populations
by either associating them with one of the core populations or dismissing them as “lone dispersers” with
only a “cursory” explanation.
Third, the court concluded that FWS had failed to explain adequately why it did not give credence to
certain studies relating to the genetic relationship between gray wolf populations. The ESA requires FWS
to use the best scientific and commercial data available when making listing decisions. In the final rule,
FWS assessed whether gray wolves in Oregon and Washington were genetically distinct from the wolves
in the Northern Rocky Mountain DPS. Although it acknowledged that gray wolves in Washington had a
mixed ancestry from Northern Rocky Mountain gray wolves and coastal gray wolves, FWS concluded
that the two groups were not distinct. The court determined that the “primary studies” on gray wolf
genetics clearly identified the “unique evolutionary heritage and adaptations” of gray wolves within the
west coast population. In the court’s view, FWS had not adequately explained why it concluded that the
Washington gray wolves were not genetically distinct in light of this science. As a result, the court held
that FWS had not used the best available science and that the agency’s decision to combine the west coast
and Northern Rocky Mountain DPS gray wolves was arbitrary and capricious.
Fourth, the court concluded that FWS had not employed a reasonable construction of the phrase
significant portion of its range when evaluating whether any gray wolf entities merited listing. The ESA
requires FWS to list a species if it is endangered or threatened in “all or a significant portion of its range.”
Accordingly, FWS must determine what makes a portion of a species’ range “significant” to assess its
status. FWS issued a joint policy with NMFS interpreting the phrase significant portion of its range in
2014, but a court vacated that policy in 2018. In its delisting rule, FWS stated that it was assessing
significance based on whether the portion of the range contributed meaningfully to “resiliency,
redundancy, or representation of the gray wolf entity” but declined to set any particular threshold for or
definition of significance. The court concluded that this approach failed to provide “objective guideposts
or factors” for the court to use in evaluating whether FWS had reasonably exercised its discretion.
Accordingly, the court could not determine whether FWS had given independent meaning to the phrase or
impermissibly rendered it superfluous.
Finally, the court determined that FWS’s analysis of the threats to the various gray wolf entities was
arbitrary and capricious because it (1) failed to analyze adequately the threats to the gray wolf across the

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entire listed species, (2) failed to consider the adequacy of existing regulatory mechanisms on federal
public lands, and (3) failed to assess adequately the effect of the loss of the gray wolf’s historical range.
The court’s first two determinations both turned on its conclusion that FWS could not rely solely on the
viability of two populations—the Northern Rocky Mountain DPS and the gray wolves in the western
Great Lakes—to delist the species across the lower 48 states and disregard threats to gray wolves
elsewhere. With respect to the gray wolf’s loss of most of its historical range in the lower 48 states, the
court did not find FWS’s assessment of the threat to gray wolves from human-caused mortality to be
sufficient to constitute adequate consideration of the effect on the gray wolf of losing that range.
Having concluded that FWS should reconsider the delisting rule in light of its decision, the court
considered whether to vacate the rule during that process. Courts may leave an agency action in place,
despite finding some error in it, if the agency seems likely to be able to correct the error on remand or if
vacatur would be disruptive. The court found that FWS’s reliance on two populations to delist the gray
wolf across the lower 48 states and its failure to interpret significant portion of its range reasonably were
sufficiently serious errors to justify vacating the rule.
Next Steps for FWS
The vacatur of the delisting rule returns the gray wolf to the ESA status it had prior to the rule’s
promulgation. As of the court’s order, the gray wolf is again listed as threatened in Minnesota and
endangered elsewhere in the lower 48 states, except for the Northern Rocky Mountain DPS. The court’s
decision does not affect the listing status of the Northern Rocky Mountain DPS. FWS may consider
whether to issue a new rule to delist the listed entities that addresses the flaws the court identified.
Separately, FWS has received two petitions related to listing gray wolf DPSs. First, it received a petition
on June 1, 2021, to relist the Northern Rocky Mountain DPS as an endangered or threatened species.
Second, FWS received a petition on July 29, 2021, to list a DPS of gray wolves in western North America
as an endangered species. The ESA requires FWS to make a finding within 90 days of receiving a
petition, to the maximum extent practical, as to whether a petition presents information indicating that the
requested action may be warranted. The ESA then requires FWS to issue a decision on each petition
within 12 months of filing that (1) denies the petition as not warranted, (2) grants the petition as
warranted along with a proposed rule to list the species, or (3) concludes that the petition is warranted but
that other agency priorities preclude listing the species at this time. Pursuant to the ESA’s procedures for
petitions, FWS issued a 90-day finding on September 17, 2021, that the petitions may be warranted. FWS
has not yet issued a 12-month finding.
The court’s decision to vacate the delisting rule may affect FWS’s decisions on the petitions. Pursuant to
the court’s order, the gray wolf is again listed in some areas covered by the petition related to western
North America. For both petitions, the requirement that FWS relist the previously delisted entities may
affect its analysis of the threats to the gray wolves in the Northern Rocky Mountain DPS.
Considerations for Congress
The status of the gray wolf under the ESA has been of interest to many Members of Congress. In 2011, an
act of Congress reinstated the rule that delisted the Northern Rocky Mountain DPS except for Wyoming.
In 2021, 85 Members submitted a letter to Secretary of the Interior Haaland asking her to revisit the
delisting decision and consider listing the gray wolf as threatened. In the wake of the court’s decision
vacating the delisting rule, Congress may consider whether to modify the status of the gray wolf via
legislation. For example, it might direct FWS to reinstate the delisting rule or to grant the petition to relist
the remaining gray wolves in the Northern Rocky Mountain DPS. Alternatively, Congress could opt not to
legislate and to allow FWS to address these issues administratively. In light of the repeated rulemakings
and litigation overturning such rules, Congress may consider whether to craft legislation specific to the

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protection or management of gray wolves in lieu of the ESA, as it did for golden and bald eagles.
Congress may also consider the listing and delisting process more broadly, and the role litigation plays in
those decisions, to ensure that the ESA is implemented as Congress intends.

Author Information

Erin H. Ward

Legislative Attorney




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