Montana GOP Gov. Greg Gianforte has signed a bill that will prohibit boys who identify as girls from participating in girls' sports in schools.
Gianforte signed the measure into law Friday, two weeks after the final version passed in the state legislature, according to CNN.
Lawmakers in roughly three dozen states have so far this year introduced such measures – with Arkansas, Mississippi and Tennessee having already signed them into law, the news site also reports.
Montana's Save Women's Sports Act states non-coed sports must be "based on biological sex" and "sports designated for females, women, or girls may not be open to students of the male sex."
The state Senate added a provision to the measure's final version that rescinds changes if the Education Department finds them to be in violation of its nondiscrimination rules. The new rules apply to college sports. The NCAA has not said whether it will respond to them being signed into law.