A Missoula District Court judge heard oral arguments Thursday in a legal challenge to House Bill 121, a Montana law requiring sex-segregated restrooms, dormitories, and locker rooms in public and some private facilities.
The Law and the Lawsuit
Judge Leslie Halligan presided over the hearing as attorneys for the plaintiffs urged the court to strike down the law entirely. The plaintiffs are current employees of state agencies who identify as transgender or intersex.
HB 121, signed by Gov. Greg Gianforte on March 22, 2025, requires multiuser bathrooms, locker rooms, and dormitories to enforce sex-based separation. The law also establishes a legal pathway for individuals to sue facilities that fail to comply with its requirements.
Arguments Before the Court
The ACLU of Montana, the national ACLU, and Legal Voice filed the lawsuit on the same day Gianforte signed the measure. A temporary block on enforcement was put in place roughly one month after the signing, halting implementation while the legal challenge proceeds.
Plaintiffs’ attorneys advanced two core constitutional arguments: first, that the law discriminates in ways that violate Montana’s constitutional guarantees of privacy and due process; second, that the statute’s definition of compliance is unconstitutionally vague, leaving facilities and individuals without clear guidance on how to follow the law.
The state, defending the law, faces the task of rebutting both the substantive constitutional claims and the vagueness challenge. No ruling was issued Thursday; Judge Halligan took the arguments under advisement.
What Comes Next
The temporary enforcement block remains in effect while Halligan deliberates. A ruling from the Missoula District Court could be appealed to the Montana Supreme Court regardless of the outcome, potentially extending the legal battle well into 2027 or beyond.
The case is one of several active legal disputes over Montana statutes touching on gender and identity. Courts across the state have seen increased activity on constitutional questions stemming from bills passed during the 2025 legislative session — including a recent Butte-Silver Bow ruling that blocked enforcement of a ballot initiative deadline, illustrating district courts’ willingness to pause contested state actions while litigation unfolds.
HB 121 was among the more prominent social-policy bills of the 2025 session, and the Gianforte administration has defended it as a straightforward matter of privacy and safety in shared facilities. Opponents contend the law effectively excludes transgender and intersex Montanans from spaces that match their identity, creating conditions for harassment and legal exposure for the individuals themselves.
Whether the challenge succeeds on the merits or the vagueness grounds — or both — will depend substantially on how Judge Halligan reads Montana’s constitution relative to the legislature’s authority to regulate public facilities.
