                              In the
    United States Court of Appeals
               For the Seventh Circuit
                          ____________

No. 05-2667
HIGHWAY J CITIZENS GROUP
and WAUKESHA COUNTY
ENVIRONMENTAL ACTION LEAGUE,
                                              Plaintiffs-Appellants,
                                 v.

UNITED STATES DEPARTMENT OF
TRANSPORTATION, MARIA CINO,1 Acting
Secretary of Transportation, FEDERAL
HIGHWAY ADMINISTRATION, et al.,
                                     Defendants-Appellees.
                      ____________
             Appeal from the United States District Court
                for the Eastern District of Wisconsin.
               No. 05 C 212—Lynn Adelman, Judge.
                          ____________
      ARGUED FEBRUARY 14, 2006—DECIDED AUGUST 2, 2006
                          ____________

    Before BAUER, RIPPLE and WILLIAMS, Circuit Judges.
 RIPPLE, Circuit Judge. In 2005, the Highway J Citizens
Group (“Citizens”) and the Waukesha County Environmen-


1
  Pursuant to Federal Rule of Appellate Procedure 43(c)(2), we
have substituted the current acting United States Secretary of
Transportation, Maria Cino, for her predecessor, Norman Mineta,
as the named respondent.
2                                                 No. 05-2667

tal Action League (“WEAL”) brought this action against the
United States Department of Transportation (“DOT”), the
Secretary of Transportation in his official capacity, the
Federal Highway Administration (“FHWA”), Mary Peters
in her official capacity as the Administrator of FHWA, the
United States Army Corps of Engineers (“Corps”), Michael
Pfenning in his official capacity as District Engineer for the
Corps, and Frank Busalacchi in his official capacity as
Secretary of the State of Wisconsin Department of Transpor-
tation (“WisDOT”). The plaintiffs alleged that federal
approval of a project to expand an eighteen-mile segment of
the former County Highway J/Wisconsin State Highway
164 violated the Administrative Procedure Act (“APA”), 5
U.S.C. § 500 et seq.; the Clean Water Act (“CWA”), 33 U.S.C.
§ 1344; the Federal-Aid Highway Act (“FAHA”), 23 U.S.C.
§ 101 et seq.; and the National Environmental Policy Act of
1969 (“NEPA”), 42 U.S.C. § 4321 et seq. The district court
denied the plaintiffs’ motion for a preliminary injunction; it
held that the plaintiffs had not demonstrated a reasonable
likelihood of success on the merits of their claims because
those claims likely were barred by claim preclusion. The
plaintiffs now appeal. They contend that the doctrine of res
judicata is not applicable to the present case because the
claims that they seek to litigate here are factually and legally
distinct from those that they litigated previously. Because
we believe that the district court correctly held that this
action is barred by res judicata, we affirm the judgment of
the district court.
No. 05-2667                                                      3

                                  I
                         BACKGROUND
A. Facts
  There are two construction projects at issue in this litiga-
tion; both are “major Federal actions”2 as defined by federal
environmental regulations.3 The first, the County


2
  The National Environmental Policy Act (“NEPA”) requires that
a recommendation for any “major Federal action[] significantly
affecting the quality of the human environment” include a
“detailed” Environmental Impact Statement (“EIS”) describing:
      (i) the environmental impact of the proposed action,
      (ii) any adverse environmental effects which cannot be
      avoided should the proposal be implemented,
      (iii) alternatives to the proposed action,
      (iv) the relationship between local short-term uses of man’s
      environment and the maintenance and enhancement of long-
      term productivity, and
      (v) any irreversible and irretrievable commitments of
      resources which would be involved in the proposed action
      should it be implemented.
42 U.S.C. § 4332(C); see also 40 C.F.R. § 1502.14 (further defining
what an EIS must contain). Federal-Aid Highway Act (“FAHA”)
regulations impose similar requirements. See 23 C.F.R. § 771.123
(setting forth applicable procedures and requiring that the “draft
EIS . . . evaluate all reasonable alternatives to the action[,] []
discuss the reasons why other alternatives, which may have been
considered, were eliminated from detailed study [and] . . .
summarize the studies, reviews, consultations, and coordina-
tion required by environmental laws or Executive Orders to the
extent appropriate at this stage in the environmental process”).
3
    See 40 C.F.R. § 1508.18 (defining a “[m]ajor Federal action” as
                                                    (continued...)
4                                                   No. 05-2667

J/Highway 164 Project (Project # 2748-01-01), involves the
expansion of an eighteen-mile segment of Wisconsin State
Highway 1644 from two to four lanes. In 1999, these eigh-
teen miles, which run through Waukesha and Washington
Counties in Wisconsin, were experiencing substantial traffic
congestion, delays and related safety issues. The Wisconsin
Department of Transportation (“WisDOT”) commissioned
a study of proposals to increase the highway’s capacity. The
WisDOT, in conjunction with the Federal Highway Admin-
istration (“FHWA”) and as required by federal law, subse-
quently drafted an Environmental Impact Statement (“EIS”)
that recommended widening the highway. See R.19, Ex.5.
The proposed expansion converts approximately 100 acres
of land for highway use and, according to the plaintiffs,
raises significant environmental concerns with regard to the
destruction of wetlands.5



(...continued)
an action “with effects that may be major and which are poten-
tially subject to Federal control and responsibility. Major rein-
forces but does not have a meaning independent of significantly
(§ 1508.27). Actions include the circumstance where the responsi-
ble officials fail to act and that failure to act is reviewable by
courts or administrative tribunals under the Administrative
Procedure Act or other applicable law as agency action”).
4
  When initially constructed in the 1970s, this highway was
designated “County Highway J.” However, in 1986, the rele-
vant section of the highway was transferred to the WisDOT
and was redesignated “Highway 164.” We therefore refer to the
road as “Highway 164” and to the project as the “Highway 164
Project” throughout this opinion.
5
   Highway 164 is located within the Upper Fox portion of the
Illinois-Fox River watershed; this area is considered a “Priority
                                                   (continued...)
No. 05-2667                                                        5

  The EIS for the project was made available to the public
on April 9, 2001, and a public hearing was held on May 30,
2001. On December 11, 2001, the FHWA and WisDOT
issued a revised EIS; this document addresses alternative
proposals raised during the hearing, but concludes in
favor of expanding the highway. The DOT and FHWA
issued a Record of Decision (“ROD”)6 on March 6, 2002,
marking their final approval of the recommendations
contained in the revised EIS. Construction by WisDOT,
using federal funds appropriated under FAHA, now has
commenced on this project. Phase I was completed in late
2004; on January 14, 2005, the Army Corps granted a permit
under § 404 of the CWA to the WisDOT to fill 9.27 acres of
wetlands, thus allowing the WisDOT to commence Phase II
of the project.
  The second project, Project # 2748-01-00, is known as the
“Ackerville Bridge/Lovers Lane Reconstruction Project”
(“Ackerville Bridge Project”). It primarily involves the
construction of two overpass structures on Highway 164 in
Washington County, near the northern end of the highway
expansion project. One overpass will cross railroad tracks,
thus eliminating the need for existing at-grade crossings; the


5
  (...continued)
Watershed” by the Wisconsin Department of Natural Resources.
See R.10, Ex.A.
6
  FAHA and NEPA regulations require the FHWA and DOT,
respectively, to certify their final approval of a major federal
action by issuing a Record of Decision (“ROD”). The ROD must
“present the basis for the [agency’s] decision” and “summarize
any mitigation measures that will be incorporated in the project.”
23 C.F.R. § 771.127(a); see also 40 C.F.R. § 1505.2(b) (requiring the
relevant agency to identify the alternatives considered and the
considerations balanced in reaching a final decision).
6                                                    No. 05-2667

second overpass will facilitate passage over State Highway
175. Like the Highway 164 expansion project, the new
overpass structures are designed to ease the flow of traffic.
  The Ackerville Bridge Project commenced with the FHWA
and WisDOT’s preparation of an Environmental Assessment
(“EA”).7 After a public hearing was held in March 2000, the
FHWA issued a “Finding of No Significant Impact”; the
FHWA concluded that the construction of the overpasses
would not affect significantly the quality of the human
environment. Construction on this project began in May
2002.




7
  NEPA regulations provide that, when the significance of the
environmental impact of a transportation project proposal is
uncertain, an Environmental Assessment (“EA”) should be
prepared to assist in making this determination. The EA should:
    (1) Briefly provide sufficient evidence and analysis for
    determining whether to prepare an environmental impact
    statement or a finding of no significant impact.
    (2) Aid an agency’s compliance with the Act when no
    environmental impact statement is necessary.
    (3) Facilitate preparation of a statement when one is neces-
    sary.
40 C.F.R. § 1508.9(a). The EA also must “include brief discussions
of the need for the proposal, . . . of the environmental impacts of
the proposed action and alternatives, and a listing of agencies
and persons consulted.” Id. § 1508.9(b). If a finding of no impact
is made, no further action is required. If, however, the agency
makes a preliminary finding that the project may result in
significant environment impacts, it must commence immediately
the preparation of an EIS.
No. 05-2667                                                7

B. The Citizens I Litigation
  Highway J Citizens Group (“Citizens”) is an unincorpo-
rated association representing citizens of Waukesha and
Washington Counties in Wisconsin “who are concerned
about the potential destruction of the region along [High-
way] 164 and [County Highway] J.” R.1 at 6. According
to the complaint in this case, Citizens’ mission includes
“maintaining Highway 164 as a two-lane scenic road[,] []
maintaining the environmental resources and preserving the
remaining rural character of the area.” Id.
   In July 2003, Citizens filed suit in the United States
District Court for the Eastern District of Wisconsin against
the Secretary of Transportation in his official capacity;
Frederick Wright in his official capacity as Executive
Director of the FHWA; and Thomas E. Carlsen in his official
capacity as Acting Secretary of the WisDOT. Citizens
alleged that the defendants’ approval of the Highway 164
and Ackerville Bridge projects violated the APA, 5 U.S.C. §§
701-06; NEPA, 42 U.S.C. § 4321 et seq.; regulations imple-
menting NEPA; and the Wisconsin Environmental Policy
Act (“WEPA”), Wis. Stat. § 1.11, Wis. Admin. Code Transp.
§ 400 et seq. Citizens first claimed that drilling for the
Ackerville Bridge Project risked disturbing an underground
“contamination plume” containing arsenic and
trichlorethylene, which was migrating towards the site of
construction. Highway J Citizens Group v. Mineta, 349 F.3d
938, 942 (7th Cir. 2003) (“Citizens I”). Citizens requested
that the court enjoin the continued construction of the
Ackerville bridges, as well as require the defendants to fill
current holes with concrete. They also asked the court to
mandate that the defendants conduct another environmen-
tal impact study; they claimed that the EA for the Ackerville
Bridge Project failed to examine the implications of the
contamination plume. Second, Citizens contended that the
8                                                   No. 05-2667

FHWA and WisDOT had failed to consider reasonable
alternatives to the building of the Ackerville bridges. Lastly,
Citizens claimed that the defendants had improperly
segmented8 the Ackerville Bridge Project from the Highway
164 Project. See Citizens I Complaint, Supp. App. at 192
(arguing that the two actions constitute “one project or, if
not, the Lovers Lane Road/Ackerville Project is an interde-
pendent part of the larger action and depends on the larger
action for its justification”). According to Citizens, both the
EIS for the Highway 164 Project and the EA and Finding of
No Significant Impact for the Ackerville Bridge Project were
incomplete because each project failed to take into account
the environmental impacts of the other. See id. at 193. As a
remedy, Citizens requested that the court require the
defendants to prepare another “[EIS] for all of the County
J/Highway 164 project,” as well as “enjoin[] the defendants
from widening County J/Highway 164 . . . from two lanes
to four lanes.” Id. at 193-94.9
 On June 12, 2003, the district court denied Citizens’
motion for a preliminary injunction and then ruled against


8
   Segmentation is a procedure that “allows an agency to avoid
the NEPA requirement that an EIS be prepared for all major
federal actions with significant environmental impacts by
segmenting an overall plan into smaller parts involving ac-
tion with less significant environmental effects.” City of West
Chicago v. United States Nuclear Regulatory Comm’n, 701 F.2d 632,
650 (7th Cir. 1983).
9
  Citizens also requested that the court enjoin the reconstruction
and realignment of Lovers Lane Road, which is considered part
of the Ackerville Bridge Project. Lovers Lane is the name of the
northern-most portion of Highway 164, after it crosses the
trackage of the Wisconsin Central Limited and the Wisconsin
Southern Railroads.
No. 05-2667                                                   9

Citizens on the merits. In pertinent part, the district court
determined that the defendants’ environmental analysis was
thorough and sufficient, as was their consideration of
feasible alternatives. The district court further found that the
defendants had made a “reasonable decision in establishing
the project termini” and that the Ackerville Project had not
been segmented improperly from the Highway 164 Project.
Id. at 179.
  Citizens appealed. We affirmed the judgment of the
district court. See Citizens I, 349 F.3d 938. We agreed with
the district court that the defendants’ environmental
analysis and consideration of alternatives were sufficient.
See id. at 952-62. We also affirmed the district court’s
holding on the segmentation issue:
    In the [EA and Finding of No Significant Impact], the
    defendants explicitly considered the three criteria
    for segmentation set out in 23 C.F.R. § 771.111, and gave
    a reasoned justification of how their segmentation fit
    each factor. As to logical termini, the defendants ex-
    plained that “[s]ince the need to bridge the train tracks
    is the driving force behind this project,” the south
    termini for the Project was established just beyond the
    bridge touchdown point.
    ...
      The second factor, independent utility, is the most
    important factor in highway cases such as this. . . . With
    respect to this factor, the [EA and Finding of No Signifi-
    cant Impact] pointed out that neither the bridge con-
    struction project, with its safety focus, or the County
    J/Highway 164 Project, with its expansion focus,
    require the construction of any other projects to be
    usable.
10                                                    No. 05-2667

       Finally, as to the third factor, restriction of alterna-
     tives, the Ackerville Bridge Project contemplates, rather
     than restricts, future roadway projects, including the
     possibility of a four-lane project if found to be needed.
     Indeed, making space for future expansion was a
     “secondary purpose” for the Project in the first place.
       In sum, the defendants analyzed the relevant factors
     set out in 23 C.F.R. § 771.111(f)(1)-(3), and came to a
     reasoned conclusion. There is also no real evidence to
     support pretextual motive. Accordingly, we hold there
     was no improper segmentation in this case.
Id. at 963 (internal citations omitted).


C. The Present Litigation
  On February 22, 2005, Citizens, together with WEAL, a
Wisconsin non-profit corporation also dedicated to protect-
ing Waukesha County’s natural resources, filed the present
lawsuit. They alleged that the DOT, FHWA and WisDOT’s
final approval of the Highway 164 Project and the Army
Corps’ issuance of a Clean Water Act § 404 permit vio-
lates the APA, 5 U.S.C. § 500 et seq., the CWA, 33 U.S.C.
§ 1344, the FAHA, 23 U.S.C. § 101 et seq. and NEPA, 42
U.S.C. § 4321 et seq.10


10
   The plaintiffs’ complaint contains eight counts. Counts I-V
allege violation of the APA and NEPA stemming from the
defendants’ failure to prepare an Environment Impact Statement
that discusses in sufficient detail the environmental effects of the
Highway 164 Project; the defendants’ reliance on unreliable and
inaccurate data with regard to the project’s impact on area
wetlands; the defendants’ failure to consider reasonable alter-
                                                    (continued...)
No. 05-2667                                                        11

  In March 2005, the plaintiffs filed a motion for a tempo-
rary restraining order (“TRO”) and a preliminary injunction,
requesting that the court enjoin the defendants from
“proceeding with any further property acquisition, demoli-
tion, grading, construction or any other physical work on
the highway 164 expansion project north of Swan Road in
Waukesha County.” R.8 at 2-3.
   On March 21, 2005, the district court11 denied the plain-
tiffs’ request for a TRO. It held that the plaintiffs had not
proven that they would suffer “irreparable injury before
[their] adversary [could] be heard.” R.13 at 2. According



10
   (...continued)
natives to expanding Highway 164, namely the improvement
of the existing two-lane highway; the defendants’ failure to
respond adequately to public comments; and the defendants’
failure to prepare a Supplemental Environmental Impact State-
ment when new information, indicating that the expansion of the
highway would have a significantly greater impact on the
surrounding environment than previously believed, became
available. Counts VI and VII allege violation of the FAHA and its
implementing regulations because the defendants did not fully
consider the adverse effects of air pollution prior to approving
the new highway project; adopt appropriate measures to mini-
mize those hazardous effects; or hold hearings at which the
public could “hear and be heard.” R.1 at 31. Count VIII alleges
that the Army Corps of Engineers violated the CWA in granting
other defendants a § 404 permit, allowing the WisDOT and
FHWA to fill in approximately nine acres of wetlands in connec-
tion with the project; the plaintiffs claim that there exist practica-
ble alternatives to destroying the wetlands, which would have a
less destructive impact on the environment.
11
  This order was issued by the district judge initially assigned to
the case. Subsequently, this judge recused himself and the case
was reassigned.
12                                                 No. 05-2667

to the court, construction on Phase II of the project was not
scheduled to begin until April 2005, and the defendants
could be heard within that time frame. The court directed
expedited proceedings on the plaintiffs’ motion for a
preliminary injunction.
  On April 27, 2005, the district court denied the plaintiffs’
motion for a preliminary injunction. See R.46. It held that the
plaintiffs had not established a “reasonable likelihood of
success on the merits of [their] claims.” Id. at 11. In pertinent
part, the court held that the plaintiffs’ current challenges to
the Highway 164 Project were barred by claim preclusion
because Citizens I: (a) culminated in a final decision on the
merits, see id. at 13 n.14; (b) involved the same parties as the
present action, or their privies, see id. at 14-16; and (c)
involved the same cause of action as the present litigation,
see id. at 17-24. Concerning the last element, the court held
that Citizens I, although focused on the Ackerville Bridge
Project and the alleged errors in the EA prepared for that
project, also challenged the EIS prepared for the widening
of Highway 164, the same document that forms the basis of
the plaintiffs’ present claims. Specifically:
     [The] plaintiffs argue that they did not challenge the
     March 6, 2002 ROD in Citizens I. . . . However, although
     Citizens never mentioned the March 6, 2002 ROD in
     Citizens I, it is clear that it challenged that decision in
     that case when it argued that the County J/Highway
     164 project was improperly segmented from the
     Ackerville Bridge project. A claim that one project was
     improperly segmented from another is necessarily
     a claim that the environmental review conducted for
     each project was inadequate because each review failed
     to consider the environmental effects of the other
     project.
Id. at 19-20 (emphasis in original).
No. 05-2667                                                 13

  In addition, the court held that the relief requested by the
plaintiffs in Citizens I demonstrated that there was an
identity between the cause of action in that litigation and the
cause of action in the present suit. See id. at 20 (“Indeed,
Citizens must have recognized that success on their segmen-
tation claim in Citizens I entailed the invalidation of the
ROD which approved the County J/Highway 164 project
because, in that case, Citizens sought to enjoin the County
J/Highway 164 project and compel FHWA and WisDOT to
prepare an EIS governing both projects.”). The court
concluded that, although the legal theories relied upon by
the plaintiffs in the present litigation are not the same as
those relied upon in Citizens I, there exists an identity of
issues between them because both cases arise from the
“same transaction” and involve “the same, or nearly the
same[,] factual allegations.” Id. at 22 (internal quotation
marks omitted).
  The plaintiffs timely filed a notice of appeal, as well as
a motion for an injunction pending appeal. See Fed. R.
Civ. P. 62(c). The district court denied this motion, deter-
mining that, because the plaintiffs had not demonstrated
a likelihood of prevailing on the merits of their claims,
an injunction pending appeal was not warranted. See R.61.
14                                                    No. 05-2667

                                 II
                         DISCUSSION
  We review de novo a district court’s denial of a motion for
a preliminary injunction on res judicata grounds.12
  Under the doctrine of res judicata, “a final judgment on
the merits of an action precludes the parties or their
privies from relitigating issues that were or could have been
raised in that action.” Allen v. McCurry, 449 U.S. 90, 94
(1980). “The three requirements for res judicata under federal
law are: (1) an identity of the parties or their privies; (2) an
identity of the causes of actions; and (3) a final judgment on
the merits.” Cent. States, S.E. & S.W. Areas Pension Fund v.
Hunt Truck Lines, Inc., 296 F.3d 624, 628 (7th Cir. 2002). If
these requirements are fulfilled, res judicata “bars not only
those issues which were actually decided in a prior suit, but
also all issues which could have been raised in that action.”
Brzostowski v. Laidlaw Waste Sys., Inc., 49 F.3d 337, 338 (7th
Cir. 1995). “Simply put, the doctrine of res judicata provides
that, when a final judgment has been entered on the merits
of a case, it is a finality as to the claim or demand in contro-
versy, concluding parties and those in privity with them,
not only as to every matter which was offered and received
to sustain or defeat the claim or demand, but as to any other
admissible matter which might have been offered for that
purpose.” Nevada v. United States, 463 U.S. 110, 129-30 (1983)
(internal quotation marks omitted).
   The plaintiffs do not contest that Citizens I resulted in
a final judgment. Nor do they dispute that, although WEAL


12
  See Matter of L & S Indus., Inc., 989 F.2d 929, 932 (7th Cir. 1993)
(holding that, although factual determinations made in the course
of evaluating a motion for a preliminary injunction are reviewed
for clear error, “legal conclusions are subject to de novo review”).
No. 05-2667                                                    15

was not a named plaintiff in the prior litigation, WEAL and
Citizens are in privity. However, they do challenge whether
the present cause of action is the same as, or has an “iden-
tity” with, the cause of action raised by Citizens in Citizens
I. A claim has “identity with a previously litigated matter if
it emerges from the same core of operative facts as that
earlier action.” Brzostowski, 49 F.3d at 338-39 (internal
quotation marks omitted). The district court, the plaintiffs
submit, mischaracterized their contentions in Citizens I.
According to the plaintiffs, the Citizens I litigation focused
exclusively on the lawfulness of the Ackerville Bridge
Project and simply did not “challenge the Highway 164
Project[].” See Reply Br. at 4-5 (citing the numerous “differ-
entiating facts between the projects”).
  We agree with the plaintiffs that the Ackerville Bridge and
Highway 164 Projects are factually distinct.13 See Citizens I,
349 F.3d at 962-63. We nevertheless must conclude that
Citizens I challenged the validity of both projects and
therefore the plaintiffs cannot relitigate claims arising out of
either project. Specifically, in Citizens I, Citizens raised the


13
   Although unnecessary to our decision today, we note the post
hoc nature of the plaintiffs’ position. Throughout the Citizens I
proceedings, the plaintiffs maintained that the two projects were,
in fact, intricately interlinked. Indeed, it is this claim that we
addressed in Citizens’ prior appeal. See Highway J Citizens Group
v. Mineta, 349 F.3d 938, 962-63 (7th Cir. 2003) (holding that the
two projects had been properly segmented).
   There is no need to address the implications of this contradic-
tion in Citizens’ position today. As we explain in the text,
although we agree with the plaintiffs that the projects are
independent, we nevertheless hold that the plaintiffs’ current
challenges to the Highway 164 Project should have been raised in
Citizens I.
16                                                  No. 05-2667

following contentions: (1) that the Finding of No Significant
Impact for the Ackerville Bridge Project failed to account for
the environmental impacts of the contamination plume; (2)
that the defendants had failed to consider “reasonably
feasible alternatives to the building of the proposed bridge,”
Citizens I Complaint, Supp. App. at 190; and (3) that the
Highway 164 and Ackerville Bridge Projects had been
segmented improperly. With regard to the last contention,
Citizens alleged that, by treating the Ackerville Bridge
Project as a separate endeavor, the defendants were able to
avoid “address[ing] the environmental issues raised by the
presence of the contaminate plume” in drafting the High-
way 164 EIS.14 Id. at 193. As a result, Citizens continued, the
Highway 164 EIS was incomplete and inaccurate.
  Notably, this previous contention arose from the same
document that forms the factual basis of the plaintiffs’
current claims. In addition, the relief requested in the
present action is similar in substantial ways to the relief
requested in Citizens I—a consideration that our cases
counsel ought to be given significant weight in determin-
ing whether there is an identity between the plaintiffs’




14
  The plaintiffs contend that these allegations are immaterial
because, in Citizens I, Citizens did not explicitly challenge the
Record of Decision (“ROD”) for the Highway 164 Project; rather,
according to the plaintiffs, the references in the Citizens I com-
plaint to Highway 164 were limited to the EIS. A ROD, however,
marks the final approval of the recommendations contained in an
EIS. Because any error in the EIS thus becomes an error in the
ROD, the documents are inseparable for the purpose of res
judicata analysis.
No. 05-2667                                                       17

causes of action for res judicata purposes.15 In Citizens I,
Citizens requested that the court “requir[e] the defendants
to prepare a Final Environmental Impact Study for all of the
County J/Highway 164 project” and “[p]reliminarily and
permanently enjoin[] the defendants from widening County
J/Highway 164.” Citizens I Complaint, Supp. App. at 193-94.
Similarly, in this litigation, the plaintiffs request that the
court “prohibit[] Defendants USDOT and FHWA from
taking any other action that in any way supports or funds
the design, property acquisition, construction or develop-
ment of the [Highway 164 expansion] project until Defen-
dants have remedied their violations of NEPA, the APA,
and federal highway law,” as well as require the defendants
to prepare a supplemental EIS for the Highway 164 Project.
R.1 at 35 (also requesting that the FHWA vacate the original
EIS and ROD for the Highway 164 Project). Accordingly, we
must conclude that, in the course of arguing that the two
projects had been improperly segmented, Citizens placed
into dispute the validity of the environmental assessment
for the Highway 164 Project.
  In our consideration of this matter, we note Citizens’ view
that the mere mention of Highway 164 in the complaint


15
   See Anchor Glass Container v. Buschmeier, 426 F.3d 872, 878 (7th
Cir. 2005) (holding that, because the “ultimate relief sought in the
two actions” is the same, “there is sufficient identity of the causes
of action [in the current and past litigations] for res judicata to
apply”); see also Friez v. First Am. & Trust of Minot, 324 F.3d 580,
581 (8th Cir. 2003) (deeming relevant to its res judicata analysis
that the plaintiff “seeks effectively the same relief (ERISA
benefits) in both cases”); United Tech. Corp. v. Chromalloy Gas
Turbine Corp., 189 F.3d 1338, 1345 (Fed. Cir. 1999) (holding that
the two suits involved identical causes of action, in part because
the “relief sought by Chromalloy in both actions is intertwined”).
18                                                  No. 05-2667

does not mean that Citizens necessarily challenged the
overall validity of the environmental assessment of
that project. They submit that, in contending that the
relevant agencies improperly segmented the two projects,
they focused primarily, or even exclusively, on errors in
assessing the environmental effects of the Ackerville Bridge
Project, referencing Highway 164 only out of necessity. We
cannot accept this argument, however. Citizens’ attempt
to minimize the significance it placed on the Highway
164 Project in Citizens I is unavailing. According to the plain
text of the documents filed in Citizens I, Citizens submitted
that segmentation was improper because it caused the
Highway 164 EIS, not the Ackerville Bridge EA, to be
underinclusive and therefore inaccurate. The thrust of
Citizens’ submission was that the improper segmentation
permitted the FHWA and WisDOT to prepare the Highway
164 EIS without first examining or accounting
for contamination issues near the Ackerville bridges. See
Citizens I Complaint, Supp. App. at 193-94 (alleging that
the “reason that the defendants have segmented the
bridge project . . . is so that the EIS for the project 2748-01-01
[the Highway 164 Project] . . . would not have to address the
environmental issues raised by the presence of the contami-
nate plume” and that, as a result, a new “Final Environmen-
tal Impact Study for all of the County J/Highway 164
project” is necessary). It is clear from these documents that,
in Citizens I, Citizens challenged the procedures followed in
preparing the environmental analysis for the Highway 164
expansion and, thus, there is an identity between the cause
of action in Citizens I and the cause of action in the present
case.
  To be sure, the plaintiffs in the present litigation do not
pursue the precise legal theories that we addressed in
Citizens I. In the prior litigation, Citizens’ only argument
No. 05-2667                                                 19

with regard to the Highway 164 Project was that the defen-
dants’ failure to take into account the environmental effects
of the contamination plume near the Ackerville bridges
rendered the EIS on that project invalid. By contrast, in the
present litigation, the plaintiffs claim that the Highway 164
EIS is inaccurate, fails to consider the cumulative environ-
mental effects of the construction or reasonable alternatives
to highway expansion, and suffers from the lack of a
meaningful opportunity for public commentary. They also
allege a violation of the FAHA on the ground that the
defendants failed to consider, and attempt to remedy,
hazardous air pollution stemming from the proposed
construction.
  However, the question is not whether the legal issues now
presented were raised previously; rather, it is whether these
matters “could have been raised in [the prior] action.”
Brzostowski, 49 F.3d at 338 (emphasis added). To determine
“whether the plaintiff could have raised the [current]
issue[s] in the first suit,” we employ a “same transaction”
test. Doe v. Allied-Signal, Inc., 985 F.2d 908, 913 (7th Cir.
1993). Under this test,
    a cause of action consists of a single core of operative
    facts giving rise to a remedy. . . . Once a transaction has
    caused injury, all claims arising from that transaction
    must be brought in one suit or lost. A plaintiff may
    not avoid an earlier judgment on the merits by merely
    concocting a new legal theory.
Id. (internal citations and quotation marks omitted).
  Here, although the legal elements of each claim may be
different, the underlying factual transaction is identical: the
20                                                    No. 05-2667

preparation and finalization of the Highway 164 EIS.16 As in
Brzostowski, the resolution of both of the plaintiffs’ com-
plaints are grounded in the adequacy of the environmental
analysis for the Highway 164 Project. See Brzostowski, 49
F.3d at 339 (“[W]e find that the two claims before us clearly
arise out of the same core of operative facts and are based
on the same factual allegations. While the legal elements of
each claim may be different, the central factual issues are
identical.”). Notably, Citizens has not argued that they were
not able to bring their present claims in the earlier litigation.
Nor could such an argument have been made. All transac-
tions forming the basis of the plaintiffs’ causes of action,
including the final approval of the Highway 164 EIS by the
FHWA and DOT, had occurred by the time Citizens I was
filed on July 3, 2002: The Highway 164 EIS was drafted and
disclosed to the public in April 2001; the ROD for the project
was issued on March 6, 2002.
  In sum, because the plaintiffs challenged the approval
of the Highway 164 Project in Citizens I, because the cur-
rent claims stem from the same factual transaction as the
legal claims addressed in that prior litigation and because


16
   We take no position on whether the plaintiffs’ CWA claim
against the Army Corps, who was not a party to the Citizens I
litigation, is also barred by res judicata. The district court
concluded that the plaintiffs had not demonstrated a reason-
able likelihood of success on their CWA claim, given that there is
no evidence that the Corps, in issuing to the WisDOT a § 404
permit, had failed to consider “practicable alternatives” to the
expansion of the highway or that the Corps understated the
wetlands impact of the project. R.46 at 24-32. The plaintiffs do not
challenge these conclusions on appeal. Therefore, this ap-
peal does not implicate the Supreme Court’s recent decision in
Rapanos v. United States, 126 S. Ct. 2208 (2006).
No. 05-2667                                                 21

the plaintiffs had a fair opportunity to raise their claims
previously, we must conclude that res judicata bars the
plaintiffs from further pursuing their challenges to the
Highway 164 Project. As the Supreme Court noted emphati-
cally in Baldwin v. Iowa State Traveling Men’s Ass’n, 283 U.S.
522, 525 (1931), “[p]ublic policy dictates that there be an end
of litigation; that those who have contested an issue shall be
bound by the result of the contest; and that matters once
tried shall be considered settled as between the parties.”


                         Conclusion
  For the foregoing reasons, we affirm the judgment of the
district court.
                                                    AFFIRMED

A true Copy:
        Teste:

                           _____________________________
                            Clerk of the United States Court of
                              Appeals for the Seventh Circuit




                     USCA-02-C-0072—8-2-06
