                   FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

BILLY SOZA WARSOLDIER,                   
                  Plaintiff-Appellant,
                   v.
                                             No. 04-55879
JEANNE WOODFORD, Director of the
                                               D.C. No.
California Department of
Corrections, in her official                CV-04-02233-
capacity; JOHN LAUDEMAN, Warden                 RSWL
of the Adelanto Community                     OPINION
Correctional Facility, in his
official capacity,
              Defendants-Appellees.
                                         
        Appeal from the United States District Court
           for the Central District of California
        Ronald S.W. Lew, District Judge, Presiding

                   Argued and Submitted
           October 6, 2004—Pasadena, California
           Submission vacated December 6, 2004
                Resubmitted June 24, 2005

                      Filed July 29, 2005

     Before: Harry Pregerson, A. Wallace Tashima, and
              Richard A. Paez, Circuit Judges.

                 Opinion by Judge Pregerson




                              8775
                   WARSOLDIER v. WOODFORD                  8779
                         COUNSEL

Audrey Huang, (Argued and Briefed), Bingham, McCutchen,
Los Angeles, California; Ben Wizner (Briefed), ACLU Foun-
dation of Southern California, Los Angeles, California, for the
plaintiff-appellant.

John E. Rittmayer (Argued) and Barry G. Thorpe (Briefed),
Deputy Attorney General, State of California, Los Angeles,
California, for the defendants-appellees.


                          OPINION

PREGERSON, Circuit Judge:

   California prisoner Billy Soza Warsoldier appeals from the
district court’s denial of his request for a preliminary injunc-
tion in his suit challenging a California Department of Correc-
tions (“CDC”) hair grooming policy, which requires that all
male inmates maintain their hair no longer than three inches.
Warsoldier refuses to adhere to the grooming policy because
of his sincere religious belief that he may cut his hair only
upon the death of a loved one. He argues that the policy, and
CDC’s refusal to permit a religious exception, violates his
right to religious freedom. We have jurisdiction pursuant to
28 U.S.C. § 1292(a)(1), and for the reasons set forth below,
we reverse the district court’s denial of Warsoldier’s request
for a preliminary injunction.

          FACTUAL AND PROCEDURAL BACKGROUND

   The facts here are undisputed by the parties. Billy Soza
Warsoldier is a Cahuilla Native American. He has partici-
pated in his tribe’s cultural, social, and religious affairs
throughout his life. One tenet of Warsoldier’s religious faith
teaches that hair symbolizes and embodies the knowledge a
8780                  WARSOLDIER v. WOODFORD
person acquires during a lifetime and that hair may be cut
only upon the death of a close relative. In keeping with his
religion, Warsoldier maintains his hair long because he
believes that cutting his hair would cost him his wisdom and
strength. He further believes that if he were to cut his hair, he
would be unable to join his ancestors in the afterlife and that
instead, the deceased members of his tribe will subject him to
taunting and ridicule. Except upon his father’s death in 1980,
Warsoldier has not cut his hair since 1971.

   From April 2, 2003 to May 27, 2004, Warsoldier was an
inmate at California’s Adelanto Community Correctional
Facility (“ACCF”), a minimum security prison located in
Adelanto, California.1 CDC’s grooming policy prohibits male
inmates from maintaining their hair longer than three inches.
15 Cal. Code Reg. § 3062(e). On April 24, 2003, Warsoldier
was given a copy of a Rules Violation Report, which alleged
that he was not in compliance with CDC’s grooming policy.
He received similar notices of violation on June 3 and June
16, 2003. The prison held hearings on each of the violations,
during which Warsoldier pleaded not guilty and asserted that
his “religious beliefs and cultural background” prevented him
from complying with the grooming policy. Nevertheless, after
each hearing, Warsoldier was found guilty of violating the
grooming policy. For his violations of the policy, Warsoldier
was punished by confinement to his cell and the imposition of
additional duty hours.

   On July 20, 2003, the prison’s Unit Classification Commit-
tee (“UCC”) designated Warsoldier a “program failure” pur-
suant to section 3062(m) of Title 15 of the California Code of
Regulations for his refusal to cut his hair.2 As punishment,
  1
     This court previously granted Warsoldier’s emergency request for a
preliminary injunction enjoining CDC from enforcing the grooming regu-
lation against Warsoldier pending this appeal. We also ordered that War-
soldier be released from custody pending this appeal.
   2
     Section 3062(m) defines a “program failure” as “[a]n inmate who fails
to comply with these grooming standards.” 15 Cal. Code Reg. § 3062(m).
                      WARSOLDIER v. WOODFORD                       8781
Warsoldier (1) lost his assignment to particular duties; (2) lost
his phone call rights; (3) was expelled from print shop and
landscaping classes; (4) was removed from his position as a
member of the Executive Body for the Inmate Advisory
Council; (5) was prohibited from going to the main yard for
recreation; (6) had his monthly draw at the prison store
reduced from $180 to $45; and (7) was prohibited from mak-
ing special purchases at the prison store.

   After Warsoldier pursued CDC’s appeal process and
exhausted all of the available administrative remedies, he
filed suit in United States District Court. Warsoldier’s suit
challenges CDC’s hair grooming regulation as violating his
right to religious freedom under the Religious Land Use and
Institutionalized Persons Act of 2000 (“RLUIPA”). Warsol-
dier’s complaint seeks preliminary and permanent injunctive
relief prohibiting CDC from punishing him for exercising his
religious beliefs and compelling CDC to lift all disciplinary
sanctions that have been imposed upon him as a consequence
of his refusal to adhere to the grooming policy. He also seeks
a declaration that applying the policy to him violates his rights
under RLUIPA.

   The district court denied Warsoldier’s request for a prelimi-
nary injunction, reasoning that because CDC had not forcibly
cut Warsoldier’s hair and had no intention of doing so before
his release, it was questionable whether Warsoldier had suf-
fered a constitutional injury. Because Warsoldier was sched-
uled to be released in eighteen days, the court concluded that
the balance of hardships did not weigh in Warsoldier’s favor
and there was no need to grant a preliminary injunction.

  Warsoldier appeals.

Such an inmate may be “subject to progressive discipline and classifica-
tion committee review for appropriate housing and program placement.
Physical force shall not be used to enforce compliance with these regula-
tions, except as permitted by existing law or with a court order.” Id.
8782                       WARSOLDIER v. WOODFORD
                                   DISCUSSION

I.       Standard of Review

   A district court’s decision regarding preliminary injunctive
relief is reviewed for an abuse of discretion. See Pharm.
Research v. Walsh, 538 U.S. 644, 660 (2003). We must
reverse the district court if it abused its discretion or based its
decision on an erroneous legal standard or on clearly errone-
ous findings of fact.3 Satava v. Lowry, 323 F.3d 805, 810 (9th
Cir. 2003). Where, as here, the district court’s ruling rests
solely on conclusions of law and the facts are either estab-
lished or undisputed, de novo review is appropriate. See Sam-
martano v. First Judicial Dist. Court, 303 F.3d 959, 964-65
(9th Cir. 2002).

II.       Preliminary Injunctive Relief4
     3
   Warsoldier argues that the district court applied an erroneous legal
standard in denying him injunctive relief. Before denying the injunction,
the district court remarked that
         [t]he Court has given this request for preliminary injunction great
         consideration and has considered all aspects of the case, and after
         having reviewed the papers and entertaining the oral argument,
         the Court makes the following ruling . . . .
According to CDC, although the district court did not explicitly state what
standard it applied, it must have relied on the right legal standard because
the court stated it had read Warsoldier’s brief, which included the correct
legal standard. We reject the suggestion that because Warsoldier included
the correct standard in his brief, that the district court necessarily applied
that standard in reaching its conclusion.
   4
     CDC argues for the first time on appeal that the Supreme Court’s deci-
sions in Heck v. Humphrey, 512 U.S. 641 (1994), and Edwards v. Balisok,
520 U.S. 641 (1997), foreclose Warsoldier’s claim for declaratory and
injunctive relief. In Heck, the Court held that a prisoner’s 42 U.S.C.
§ 1983 action to recover damages based on an invalid conviction or sen-
tence may only be brought after “the conviction or sentence has been
reversed on direct appeal, expunged by executive order, declared invalid
by a state tribunal authorized to make such determination, or called into
                       WARSOLDIER v. WOODFORD                           8783
   “To obtain a preliminary injunction, [Warsoldier] must
show either (1) a likelihood of success on the merits and the
possibility of irreparable injury or (2) the existence of serious
questions going to the merits and the balance of hardships tip-
ping in [Warsoldier’s] favor.” See Nike, Inc. v. McCarthy, 379
F.3d 576, 580 (9th Cir. 2004) (quoting Gilder v. PGA Tour,
Inc., 936 F.2d 417, 422 (9th Cir. 1991)) (internal quotations
omitted). “These two alternatives represent extremes of a sin-
gle continuum, rather than two separate tests. Thus, the
greater the relative hardship to [Warsoldier], the less probabil-
ity of success must be shown.” See Walczak v. EPL Prolong,
Inc., 198 F.3d 725, 731 (9th Cir. 1999) (internal quotations
omitted).

A.   Likelihood of Success on the Merits

   [1] Section 3 of RLUIPA provides, in relevant part, that
“[n]o government shall impose a substantial burden on the
religious exercise of a person residing in or confined to an
institution . . . even if the burden results from a rule of general

question by a federal court’s issuance of a writ of habeas corpus, 28
U.S.C. § 2254.” 512 U.S. at 487. Balisok took this reasoning one step fur-
ther and applied Heck to a prisoner’s § 1983 claim for damages and
declaratory relief based on the allegedly invalid procedures used to
deprive him of good-time credits. 520 U.S. at 648.
   Our decision, however, does not rely on CDC’s denial of Warsoldier’s
good-time credits; Heck and Balisok therefore have no application here.
Warsoldier was first notified of his extended parole date on May 11, 2004
—after the district court denied his motion for a preliminary injunction.
Because the factual basis for CDC’s Heck argument is undeveloped, the
district court has not had the opportunity to consider the question in the
first instance, and the extension of Warsoldier’s incarceration is not a basis
for our holding here, we decline to address CDC’s argument that Warsol-
dier’s RLUIPA claim must be brought in a habeas proceeding. CDC may
raise this issue on remand to the district court should Warsoldier challenge
his loss of good-time credits. We express no opinion on the merits of
CDC’s argument that Heck and Balisok should be extended to apply to
RLUIPA claims in general or to the specific facts of this case.
8784                   WARSOLDIER v. WOODFORD
applicability,” unless the government establishes that the bur-
den furthers “a compelling governmental interest,” and does
so by “the least restrictive means.”5 42 U.S.C. § 2000cc-
1(a)(1)-(2). RLUIPA defines “religious exercise” to include
“any exercise of religion, whether or not compelled by, or
central to, a system of religious belief.” § 2000cc-5(7)(A). “A
person may assert a violation of [RLUIPA] as a claim or
defense in a judicial proceeding and obtain appropriate relief
against a government.” § 2000cc-2(a).

   The Supreme Court recently upheld RLUIPA against a
challenge under the Establishment Clause. Cutter v. Wilkin-
son, 125 S.Ct. 2113 (2005). In Cutter, the Court found that
RLUIPA’s institutionalized-persons provision was compatible
with the Court’s Establishment Clause jurisprudence and con-
cluded that RLUIPA “alleviates exceptional government-
created burdens on private religious exercise.” Id. at 2121. In
upholding the act, the Court recognized RLUIPA “[a]s the lat-
est of long-running congressional efforts to accord religious
exercise heightened protection from government-imposed
burdens,” id. at 2117, and that Congress sought to provide
inmates a mechanism to seek redress against the “ ‘frivolous
or arbitrary’ barriers [that] impeded institutionalized persons’
religious exercise,” id. at 2119; see also id. at 2115 (noting
that RLUIPA’s purpose is to “protect[ ] institutionalized per-
sons who are unable freely to attend to their religious needs
and are therefore dependent on the government’s permission
and accommodation of their religion”). Congress did this by
replacing the “legitimate penological interest” standard articu-
lated in Turner v. Safley, 482 U.S. 78, 89 (1987), with the
“compelling governmental interest” and “least restrictive
means” tests codified at 42 U.S.C. § 2000cc-1(a). See also
Cutter, 125 S.Ct. at 2119.
   5
     Section 3 applies when “the substantial burden [on religious exercise]
is imposed in a program or activity that receives Federal financial assis-
tance,” such as the federal funds California accepts for the operation of its
prisons. § 2000cc-1(b)(1). The parties do not dispute that RLUIPA applies
to California prisons.
                        WARSOLDIER v. WOODFORD                          8785
   Under RLUIPA, Warsoldier bears the initial burden of
going forward with evidence to demonstrate a prima facie
claim that CDC’s grooming policy and its punitive sanctions
designed to coerce him to comply with that policy constitute
a substantial burden on the exercise of his religious beliefs.
See 42 U.S.C. § 2000cc-2(b).6 If Warsoldier establishes the
prima facie existence of such a substantial burden, on which
he bears the burden of persuasion, the CDC shall bear the bur-
den of persuasion to prove that any substantial burden on
Warsoldier’s exercise of his religious beliefs is both “in fur-
therance of a compelling governmental interest” and the
“least restrictive means of furthering that compelling govern-
mental interest.” 42 U.S.C. § 2000cc-1(a); § 2000cc-2(b). By
its terms, RLUIPA is to be construed broadly in favor of pro-
tecting an inmate’s right to exercise his religious beliefs. 42
U.S.C. § 2000cc-3(g) (“This chapter shall be construed in
favor of a broad protection of religious exercise, to the maxi-
mum extent permitted by the terms of this chapter and the
Constitution.”).

  1.     Substantial Burden

  CDC regulations provide that

       A male inmate’s hair shall not be longer than three
       inches and shall not extend over the eyebrows or
       below the top of the shirt collar while standing
  6
   Section 2000cc-2 provides that,
      If a plaintiff produces prima facie evidence to support a claim
      alleging a violation of the Free Exercise Clause or a violation of
      section 2000cc of this title, the government shall bear the burden
      of persuasion on any element of the claim, except that the plain-
      tiff shall bear the burden of persuasion on whether the law
      (including a regulation) or government practice that is challenged
      by the claim substantially burdens the plaintiff’s exercise of reli-
      gion.
42 U.S.C. § 2000cc-2(b).
8786               WARSOLDIER v. WOODFORD
    upright. Hair shall be cut around the ears, and side-
    burns shall be neatly trimmed, and shall not extend
    below the mid-point of the ear.

15 Cal. Code Reg. § 3062(e). In contrast,

    A female inmate’s hair may be any length but shall
    not extend over the eyebrows or below the bottom of
    the shirt collar while standing upright. If hair is long,
    it shall be worn up in a neat, plain style, which does
    not draw undue attention to the inmate.

15 Cal. Code Reg. § 3062(f). Section 3062(e) makes no
exception for religious adherents whose faith prohibits them
from cutting their hair. Warsoldier argues that CDC’s groom-
ing policy—in particular its failure to provide for a religious
exception—imposes a substantial burden on the exercise of
his religion, which prohibits him from cutting his hair.

   [2] Although RLUIPA does not define what constitutes a
“substantial burden” on religious exercise, see 42 U.S.C.
§ 2000cc-5, in the context of a land use suit brought under
RLUIPA, we have explained that “for a land use regulation to
impose a ‘substantial burden,’ it must be ‘oppressive’ to a
‘significantly great’ extent. That is, a ‘substantial burden’ on
‘religious exercise’ must impose a significantly great restric-
tion or onus upon such exercise,” San Jose Christian Coll. v.
City of Morgan Hill, 360 F.3d 1024, 1034 (9th Cir. 2004). In
addition, the Supreme Court has found a substantial burden as
“where the state . . . denies [an important benefit] because of
conduct mandated by religious belief, thereby putting substan-
tial pressure on an adherent to modify his behavior and to vio-
late his beliefs.” Thomas v. Review Bd. of the Ind.
Employment Sec. Div., 450 U.S. 707, 717-18 (1981) (ruling in
First Amendment context). Although such “compulsion may
be indirect, the infringement upon free exercise is nonetheless
substantial.” Id. at 718.
                   WARSOLDIER v. WOODFORD                  8787
   As a consequence of his refusal to cut his hair in violation
of his religious beliefs, Warsoldier has been subjected to a
series of punishments designed by CDC to coerce him into
compliance. He has (1) been confined to his cell; (2) had addi-
tional duty hours imposed on him; (3) been reclassified into
a workgroup where inmates do not receive time credits or as
many privileges as others working in a higher work group; (4)
lost his phone call privileges; (5) been expelled from print
shop and landscaping classes; (6) been removed from his
position as a member of the Executive Body for the Inmate
Advisory Council; (7) been prohibited from going to the main
yard for recreation; (8) had his monthly draw at the prison
store reduced from $180 to $45; and (9) been prohibited from
making special purchases at the prison store. According to
CDC’s statement of reasons supporting its grooming policy,
such punishments are “necessary to make complying with the
grooming standards more of an appealing choice to the
inmate.”

   [3] Notwithstanding these assorted punishments, CDC
advances the argument, accepted by the district court, that
because Warsoldier has not been physically forced to cut his
hair, his religious practice has not been restricted. According
to CDC, even though he has been subjected to a variety of
punishments for refusing to yield on his religious beliefs,
Warsoldier is still “free to exercise his religion in all
respects.” In other words, the grooming policy is not a sub-
stantial burden because Warsoldier may practice his religion
—he will just be punished for doing so in an effort to compel
him to acquiesce with the grooming policy in contravention
of his religious beliefs. Such an argument flies in the face of
Supreme Court and Ninth Circuit precedent that clearly hold
that punishments to coerce a religious adherent to forgo her
or his religious beliefs is an infringement on religious exer-
cise. See e.g., Sherbert v. Verner, 374 U.S. 398, 404 (1963)
(reasoning that forcing someone “to choose between follow-
ing the precepts of her religion and forfeiting benefits, on the
one hand, and abandoning one of the precepts of her religion
8788                WARSOLDIER v. WOODFORD
in order to accept work, on the other hand . . . . puts the same
kind of burden upon the free exercise of religion as would a
fine imposed against appellant for her Saturday worship”);
May v. Baldwin, 109 F.3d 557, 563 (9th Cir. 1997) (noting
“that ‘putting substantial pressure on an adherent to modify
his behavior and to violate his beliefs’ infringes on the free
exercise of religion”) (quoting Thomas, 450 U.S. at 718).

   [4] Because the grooming policy intentionally puts signifi-
cant pressure on inmates such as Warsoldier to abandon their
religious beliefs by cutting their hair, CDC’s grooming policy
imposes a substantial burden on Warsoldier’s religious prac-
tice. See May, 109 F.3d at 563 (finding substantial burden
where prison officials conditioned receipt of benefits upon
conduct—undoing of inmate’s dreadlocks—that was pro-
scribed by Rastafarian inmate’s religious faith); see also
Thomas, 450 U.S. at 717-18; Sherbert, 374 U.S. at 404 n.5
(“Under some circumstances, indirect ‘discouragements’
undoubtedly have the same coercive effect upon the exercise
of First Amendment rights as imprisonment, fines, injunctions
or taxes.”); Planned Parenthood v. Arizona, 718 F.2d 938,
942 (9th Cir. 1983) (“The Supreme Court has clearly articu-
lated that government may not restrict exercise of constitu-
tionally protected rights, even when that restriction takes the
form of withholding a benefit, rather than applying a penalty,
for that exercise.”).

  2.   Compelling State Interest

   Because we find that CDC’s grooming policy imposes a
substantial burden on Warsoldier’s religious exercise, CDC
must establish that the policy serves a compelling governmen-
tal interest. See 42 U.S.C. § 2000cc-1(a); 42 U.S.C. § 2000cc-
2(b).

   According to CDC, three compelling interests are served by
its hair grooming policy. First, the hair length standards facili-
tate the security of prison inmates and staff by allowing the
                      WARSOLDIER v. WOODFORD                       8789
quick and accurate identification of inmates. In addition,
inmates may hide contraband or weapons in their hair or on
their bodies. Absent the grooming standards, prison guards
would be forced to make physical contact with an inmate to
check for contraband. During such contact, prison guards risk
suffering a puncture wound from sharp implements possibly
concealed in the inmate’s long hair. Further, such policies
reduce animosity and tension by removing a method by which
inmates may signal a gang affiliation. Second, because short
hair is easier to keep clean, requiring that male inmates main-
tain short hair reduces the spread of head-borne parasites such
as lice within the prison. Health and safety are also further
facilitated by short hair, because it reduces the risk of injury
during the inmate’s use of heavy machinery. Finally, CDC
argues that requiring male inmates to cut their hair ensures
public safety because it “enhance[s] identification of inmates
who are attempting to escape or who have escaped.” In addi-
tion, requiring short hair prevents prisoners from easily dis-
guising their identity by cutting their hair upon their escape.

   In support of its argument, CDC cites three out-of-circuit
cases upholding prison grooming policies as serving a com-
pelling interest under the strict-scrutiny standard of RLUI-
PA’s predecessor, the Religious Freedom Restoration Act
(“RFRA”).7 These cases are not dispositive, however. In two
of the cases the regulations were upheld against challenges
brought by inmates of maximum security facilities. See Har-
ris v. Chapman, 97 F.3d 499, 503-04 (11th Cir. 1996) (finding
state’s “compelling interest in security and order within their
prisons” especially applies “in ‘close custody’ facilities like
MCI which contain extremely violent offenders”); Hamilton
v. Schriro, 74 F.3d 1545, 1555 (8th Cir. 1996) (“It is more
than merely ‘eminently reasonable’ for a maximum security
  7
   There exists little Ninth Circuit authority construing RLUIPA. Thus,
the parties rely in part on cases construing its predecessor, RFRA, which
the Supreme Court struck down as applied to the states in City of Bourne
v. Flores, 521 U.S. 507 (1997).
8790                    WARSOLDIER v. WOODFORD
prison to prohibit inmates from having long hair in which they
could conceal contraband and weapons. It is compelling.”). In
contrast here, Warsoldier was incarcerated in ACCF, a mini-
mum security facility. In the third case, Diaz v. Collins, the
Fifth Circuit upheld a prison grooming policy requiring that
male inmates maintain short hair without discussing whether
any other less restrictive means that could accomplish the
same compelling interest were offered by the inmate or
rejected by the prison. 114 F.3d 69, 72-73 (5th Cir. 1997).
But, under RLUIPA, CDC is required to demonstrate not only
that its policy serves a compelling interest, but also that it has
employed the least restrictive means to achieve that compel-
ling interest. See 42 U.S.C. § 2000cc-1(a); 42 U.S.C.
§ 2000cc-2(b).

   CDC also cites Friedman v. Arizona, 912 F.2d 328, 331-32
(9th Cir. 1990), in support of its argument that its stated inter-
ests are legitimate. CDC’s reliance on Friedman is misplaced
because that case was decided under the pre-RLUIPA stan-
dard articulated in Turner, which upheld a prison regulation
impinging on inmates’ constitutional rights where the regula-
tion “is reasonably related to legitimate penological interests.”8
  8
   In Henderson v. Terhune, 379 F.3d 709 (9th Cir. 2004), we considered
a similar challenge to CDC’s hair length regulation brought under 42
U.S.C. § 1983. In that case, we applied Turner and concluded that the reg-
ulation served a legitimate penological interest and did not infringe upon
the exercise of Native American religious beliefs in violation of the First
Amendment. Id. at 712-15. The panel noted, however, that
      We express no opinion about whether the CDC’s hair length reg-
      ulation violates the Religious Land Use & Institutionalized Per-
      sons Act (“RLUIPA”), which provides that the government may
      not impose a substantial burden on an inmate’s exercise of reli-
      gion unless the regulation in question furthers a compelling state
      interest in the least restrictive manner. 42 U.S.C. § 2000cc-1(a);
      Mayweathers v. Newland, 314 F.3d 1062, 1070 (9th Cir. 2002)
      (upholding RLUIPA’s constitutionality). Henderson brought his
      claim under the First Amendment, not the RLUIPA, so here we
      apply only Turner’s “reasonable relation” standard.
Id. at 715 n.1.
                   WARSOLDIER v. WOODFORD                  8791
482 U.S. at 89. RLUIPA replaced Turner’s “legitimate peno-
logical interest” test with a “compelling government interest”
test. See 42 U.S.C. § 2000cc-1(a). Similarly, in arguing that
it has met its evidentiary burden, CDC cites cases that all pre-
date passage of RLUIPA and involve claims subjected to the
lower standard of a “legitimate penological interest” versus
RLUIPA’s “compelling government interest” standard. Com-
pare Swift v. Lewis, 901 F.2d 730, 731 (9th Cir. 1990) (citing
Turner, 482 U.S. at 89, and noting that “[p]rison regulations
that infringe on an inmate’s practice of his religion are valid
if they are ‘reasonably related to legitimate penological inter-
ests’ ”), with 42 U.S.C. § 2000cc-1(a) (government must
establish that burden is “in furtherance of a compelling gov-
ernmental interest”).

   Nevertheless, the question here is not whether prison secur-
ity is a compelling governmental interest. It clearly is. See
Pell v. Procunier, 417 U.S. 817, 823 (1974); see also May,
109 F.3d at 563 (noting that security during transfer of
inmates is compelling interest). Rather, the question is
whether CDC’s grooming policy is the least restrictive alter-
native available to CDC to reach its compelling interest.

  3.   Least Restrictive Alternative

   [5] Assuming that CDC has met its evidentiary burden, and
that it has established that the grooming policy serves a com-
pelling governmental interest, CDC must still establish that
the grooming policy is the least restrictive alternative to
achieve that interest. See 42 U.S.C. § 2000cc-1(a); 42 U.S.C.
§ 2000cc-2(b). This it has failed to do.

   In attempting to meet its burden, CDC presents only con-
clusory statements that the hair grooming policy is the least
restrictive means to ensuring prison security. First, CDC
states that “[a]ll other modes of regulation would either overly
burden the inmate or the penal institution, or conversely fail
to meet the compelling penological interests achieved by the
8792               WARSOLDIER v. WOODFORD
grooming standards.” CDC does not elaborate why this is the
case or what other modes of regulation it considered and
rejected. Instead, CDC relies on four out-of-circuit cases
where courts upheld grooming policies as the least restrictive
means. As noted above, these cases dealt with grooming stan-
dards in maximum security prisons.

   [6] In contrast here, Warsoldier was placed in a minimum
security prison. Inmates at facilities such as ACCF have a
greater degree of freedom than inmates at higher security
facilities precisely because they pose fewer security risks.
ACCF inmates have less serious criminal histories, are serv-
ing minimal sentences, and are less likely to attempt to
escape. Additionally, inmates in low-level security facilities
may be permitted to leave the premises to work and may sleep
in unlocked dorm rooms rather than locked prison cells.
Given the reduced security pressures at such minimum secur-
ity facilities, the least restrictive means in a maximum secur-
ity prison may not be identical to what is required for a
minimum security facility. CDC does not address this differ-
ence.

   [7] Moreover, even outside the context of a minimum
security facility, CDC cannot meet its burden to prove least
restrictive means unless it demonstrates that it has actually
considered and rejected the efficacy of less restrictive mea-
sures before adopting the challenged practice. See United
States v. Playboy Entm’t Group, Inc., 529 U.S. 803, 824
(2000) (finding, in context of First Amendment challenge to
speech restrictions, that “[a] court should not assume a plausi-
ble, less restrictive alternative would be ineffective”); City of
Richmond v. J.A. Croson, 488 U.S. 469, 507 (1989) (holding
that city’s minority set-aside program was not narrowly tai-
lored in part because city had not considered whether race-
neutral measures would have achieved government’s interest);
Hunter ex rel. Brandt v. Regents of Univ. of Cal., 190 F.3d
1061, 1078 (9th Cir. 1999) (concluding that government “ne-
glected to undertake any consideration—let alone serious,
                     WARSOLDIER v. WOODFORD                      8793
good faith consideration” of race-neutral alternatives (internal
quotation marks and citation omitted)). For instance, one
alternative to CDC’s rigid policy would be the creation of a
religious exemption to the grooming policy. Rather, CDC
simply states that “[t]o meet the penological interests fur-
thered by the grooming standard, the prison must enforce the
grooming policies upon all inmates regardless of their reli-
gious convictions.” It does nothing to explain why this is so
or to discuss whether it has ever considered a less restrictive
approach.

   [8] Equally problematic for CDC is that other prison sys-
tems, including the Federal Bureau of Prisons, do not have
such hair length policies or, if they do, provide religious
exemptions. Prisons run by the federal government, Oregon,
Colorado, and Nevada all meet the same penological goals
without such a policy. Nevada permits inmates “freedom in
personal grooming.” Nev. Dep’t of Corrections Admin. Reg.
705.01(1.1).9 Similarly, Colorado’s Department of Correc-
tions has no hair length requirement and expressly provides
for a religious exemption to its grooming regulations. Colo.
Admin. Reg. 850-11(I); (IV)(A)(1)(d).10 Oregon merely
requires that an inmate’s “[h]ead and facial hair . . . be main-
tained in a clean and neat manner.” Or. Admin. R. § 291-123-
0015(2)(a).11 Nor does the federal Bureau of Prisons impose
any mandatory restrictions on its inmates’ hair length, regard-
less of the prison’s security level. U.S. Dep’t of Justice, Fed.
Bureau of Prisons, Program Statement 5230.05 § 551.4.12
Indeed, “[f]or more than a decade, the federal Bureau of Pris-
ons has managed the largest correctional system in the Nation
under the same heightened scrutiny standard as RLUIPA
  9
   Available at http://www.doc.nv.gov.
  10
     Available at http://www.doc.state.co.us/admin_reg/PDFs/
0850_11.pdf.
  11
     Available at http://arcweb.sos.state.or.us/rules/OARS_200/OAR_291/
291_123.html.
  12
     Available at http://bop.gov/DataSource/execute/dsPolicyLoc.
8794                WARSOLDIER v. WOODFORD
without compromising prison security, public safety, or the
constitutional rights of other prisoners.” Cutter, 125 S.Ct. at
2124 (quoting Brief for United States at 24).

   Surely these other state and federal prison systems have the
same compelling interest in maintaining prison security,
ensuring public safety, and protecting inmate health as CDC.
Nevertheless, CDC offers no explanation why these prison
systems are able to meet their indistinguishable interests with-
out infringing on their inmates’ right to freely exercise their
religious beliefs. Instead, CDC argues that its prisons should
not be hindered in addressing its compelling interests just
because other jurisdictions have adopted policies that do not
substantially burden inmates’ religious practices.

   Contrary to CDC’s argument, we have found comparisons
between institutions analytically useful when considering
whether the government is employing the least restrictive
means. Indeed, the failure of a defendant to explain why
another institution with the same compelling interests was
able to accommodate the same religious practices may consti-
tute a failure to establish that the defendant was using the
least restrictive means. See Cheema v. Thompson, 67 F.3d
883, 885 n.3 (9th Cir. 1995) (finding fault with defendant’s
failure to explain fact that another school district had man-
aged to accommodate Sikh students’ religious practices with-
out sacrificing school safety). Furthermore, “[w]here a
prisoner challenges the[ prison’s] justifications, prison offi-
cials must set forth detailed evidence, tailored to the situation
before the court, that identifies the failings in the alternatives
advanced by the prisoner.” May, 109 F.3d at 564-65 (empha-
sis added).

  [9] CDC also fails to explain why its women’s prisons do
not adhere to an equally strict grooming policy even in maxi-
mum security facilities. In contrast to the men’s grooming
policy at issue here, CDC regulations provide that
                      WARSOLDIER v. WOODFORD                        8795
       A female inmate’s hair may be any length but shall
       not extend over the eyebrows or below the bottom of
       the shirt collar while standing upright. If hair is long,
       it shall be worn up in a neat, plain style, which does
       not draw undue attention to the inmate.

15 Cal. Code Reg. § 3062(f). As Warsoldier points out, the
government’s interest in inmate health and security is no less
compelling when the inmate is female rather than male. Con-
cerns about inmate identification, lice infestation, and the ease
with which an escaped inmate may alter her or his appearance
are the same regardless of the sex of the offender. That CDC’s
compelling interests apply equally to male and female inmates
suggests that there is no particular health or security concern
justifying the policy, and, more importantly, that the hair
length restriction is not the least restrictive means to achieve
the same compelling interests.

   Challenging this comparison, CDC argues that the differ-
ence in treatment between male and female inmates is justi-
fied because women inmates are “much less likely” to commit
violent crimes than male inmates and, hence, that women
inmates pose a lesser security concern. However, the evidence
cited by CDC does not clearly bear this out. According to
CDC’s data, female inmates commit assaults and/or batteries
at a rate of 3.2 per 100 inmates. In comparison, male inmates
commit 4.7 assaults and/or batteries per 100 inmates. A dif-
ference of 1.5 percent hardly suggests that female inmates are
“much less likely” to commit assaults than male inmates. Fur-
thermore, the data cited by CDC does not indicate whether it
is based on California’s entire prison population, which would
include maximum security facilities, or is limited to minimum
security facilities like ACCF. Warsoldier was incarcerated at
a minimum security facility, which is likely to have signifi-
cantly different security needs than a maximum security facili-
ty.13
  13
    Equally misplaced is CDC’s reliance on out-of-circuit equal protection
cases approving differential treatment between male and female prisoners
8796                  WARSOLDIER v. WOODFORD
   CDC makes no attempt to explain why prisons in other
jurisdictions and its own women’s prisons are able to meet the
same compelling interests of prison safety and security with-
out requiring short hair or permitting a religious exemption.
Instead, CDC insists that this court must completely defer to
CDC’s judgment. CDC’s insistence, however, is insufficient
to meet its burden of proof under § 2000cc-2(b). See May,
109 F.3d at 564-65 (“Our holding should not suggest that
prison officials can satisfy the demands of RFRA with mere
assertions of unfulfilled security objectives.”).

  4.    Conclusion

   [10] Based on the above, we find that Warsoldier has dem-
onstrated a likelihood that he will prevail on the merits. While
we recognize that CDC’s interest in maintaining prison secur-
ity is compelling, CDC’s conclusory statements are insuffi-
cient to meet its burden that it has adopted the least restrictive
means to achieve that interest. At a minimum, there exists
serious questions going to the merits of Warsoldier’s claim.

B.     Possibility of Irreparable Injury

   For the same reasons the grooming policy constitutes a sub-
stantial burden on Warsoldier’s religious practice, we con-
clude that Warsoldier faces the possibility of irreparable
injury absent an injunction barring enforcement of the groom-
ing policy. Because his religion forbids him from cutting his
hair, CDC’s grooming policy and its continual punishment of
Warsoldier’s noncompliance with that policy forces Warsol-

vis-a-vis grooming standards. The cases cited all involve equal protection
claims by male prisoners that were subject to rational basis analysis or
intermediate scrutiny analysis. See Dreibelbis v. Marks, 742 F.2d 792,
795-96 (3d Cir. 1984); Deblasio v. Johnson, 128 F. Supp. 2d 315, 328
(E.D. Va. 2000); and Davie v. Wingard, 958 F. Supp. 1244, 1252-53 (S.D.
Ohio 1997). In contrast, under RLUIPA, CDC’s regulations must survive
strict scrutiny analysis. 42 U.S.C. § 2000cc-1(a).
                    WARSOLDIER v. WOODFORD                   8797
dier to choose between following his religious beliefs and suf-
fering continual punishment, and abandoning his religious
beliefs to avoid such punishment. We have previously held
that “ ‘putting substantial pressure on an adherent to modify
his behavior and to violate his beliefs’ infringes on the free
exercise of religion.” May, 109 F.3d at 563 (quoting Thomas,
450 U.S. at 718); see also Sherbert, 374 U.S. at 404 (noting
that forcing someone “to choose between following the pre-
cepts of her religion and forfeiting benefits, on the one hand,
and abandoning one of the precepts of her religion in order to
accept work, on the other hand. . . . puts the same kind of bur-
den upon the free exercise of religion as would a fine imposed
against appellant for her Saturday worship”).

   [11] Finally, “[u]nder the law of this circuit, a party seeking
preliminary injunctive relief in a First Amendment context
can establish irreparable injury sufficient to merit the grant of
relief by demonstrating the existence of a colorable First
Amendment claim.” See Sammartano, 303 F.3d at 973-74
(internal citations omitted); see also 11A Charles Alan Wright
& Arthur R. Miller, Federal Practice and Procedure, § 2948.1
(2d ed. 2004) (“When an alleged deprivation of a constitu-
tional right is involved, most courts hold that no further show-
ing of irreparable injury is necessary.”). Because Warsoldier
has, at a minimum, raised a colorable claim that the exercise
of his religious beliefs has been infringed, he has sufficiently
established that he will suffer an irreparable injury absent an
injunction barring enforcement of the grooming policy against
him.

C.   Balance of Hardships

   [12] Contrary to the district court’s conclusion, the fact that
Warsoldier was due to be released in eighteen days does not
mean that the balance of hardships weigh against him: “[T]he
loss of First Amendment freedoms, for even minimal periods
of time, unquestionably constitutes irreparable injury” for pur-
poses of the issuance of a preliminary injunction. Elrod v.
8798                WARSOLDIER v. WOODFORD
Burns, 427 U.S. 347, 373 (1976). Rather, this case raises seri-
ous First Amendment questions and compels a finding that
the potential for irreparable injury exists, or at the very least,
that “the balance of hardships tips sharply in [Warsoldier’s]
favor.” See Sammartano, 303 F.3d at 973 (internal citations
and quotations omitted).

   [13] Balanced against the irreparable injury faced by War-
soldier is CDC’s compelling interest in maintaining prison
security, health, and hygiene. In considering which way the
balance tilts, it is important to note that, unlike the cases cited
by CDC, which involved maximum security prisons, ACCF
is a minimum security prison. Based on these facts, we find
that the balance of hardships here tilt in Warsoldier’s favor,
and thus, that the district court erred in denying him prelimi-
nary injunctive relief. See Elrod, 427 U.S. at 373-74 (holding
that when the loss of First Amendment freedoms “[i]s both
threatened and occurring at the time of [plaintiff’s] motion
and [if] [plaintiff] sufficiently demonstrated a probability of
success on the merits, the Court of Appeals might properly
have held that the District Court abused its discretion in deny-
ing preliminary injunctive relief”).

                          CONCLUSION

   [14] RLUIPA requires that CDC use the least restrictive
means necessary to achieve its compelling interest in prison
safety and security. 42 U.S.C. § 2000cc-1(a); see Cutter, 125
S.Ct. at 2119. The policy at issue here is sweeping: it applies
to all male inmates, but to no female inmates regardless of a
female inmate’s security threat; it does nothing to distinguish
between inmates housed at maximum security facilities and
those low level offenders in minimum security institutions;
and it provides absolutely no accommodation for religious
belief. Yet, CDC has utterly failed to demonstrate that the dis-
puted grooming policy is the least restrictive means necessary
to ensure prison safety and security. Because Warsoldier has
established a likelihood of success on the merits and the pos-
                    WARSOLDIER v. WOODFORD                   8799
sibility that the grooming policy will cause him to suffer an
irreparable injury, the district court’s denial of his request for
a preliminary injunction prohibiting CDC from enforcing its
hair grooming policy is REVERSED and the cause is
REMANDED to the district court for further proceedings not
inconsistent with this opinion. Our previous injunction enjoin-
ing CDC from enforcing the grooming regulation against
Warsoldier and releasing Warsoldier from custody pending
this appeal shall remain in place pending entry of a final judg-
ment in the district court.
