Voters in four western states approved ballot measures this week barring transgender athletes from girls’ sports.

Washington and Arizona both passed measures to ban transgender athletes from competing on girls’ teams, while a similar proposal in Colorado was narrowly leading Thursday as votes continued to be counted.

Nebraska voters also overwhelmingly approved a constitutional amendment enshrining the state’s existing ban on transgender athletes in girls’ and women’s sports.

In deep-blue Washington, Initiative 638 passed with 56.6% of the vote, , according to the secretary of state’s office. Just four of the state’s 39 counties voted against the measure.

The initiative ends a policy the Washington Interscholastic Activities Association has followed since 2007, allowing transgender students to compete on K-12 teams matching their gender identity.

Under the measure, students assigned male at birth will be barred from competing on girls’ school sports teams.

Girls seeking to participate will need a signed statement from a health care provider verifying their biological sex, based on reproductive anatomy, genetics or natural testosterone levels.

The measure is set to take effect Dec. 3, though opponents could sue to block its implementation.

Arizona’s Proposition 318 also passed, winning 58.9% of the vote.

Unlike Washington’s initiative, Prop. 318 was referred to voters by the state Legislature. It requires public schools, private schools and athletic associations to designate teams as male, female or coed based on the sex recorded on a student’s original birth certificate.

The measure also bars transgender students from using locker rooms, restrooms and other athletic facilities that do not match their sex at birth.

It effectively revives a 2022 state law that a federal appeals court blocked in 2024. Arizona Democratic Attorney General Kris Mayes had refused to defend the law in court.

“This is a historic week for girls and common sense. For years we’ve been told that protecting girls’ sports was a fringe position. Well it is not! Tuesday proved that wrong,” Sophia Lorey from the California Family Council told the California Post.

“Biology is not a partisan issue. Every girl who trains before dawn, gives up weekends and sacrifices to compete deserves a level playing field,” she added.

Golden State voters had no such measure on their ballot this year.

Protect Kids California tried to qualify a measure for the 2024 ballot that would have repealed the state law allowing transgender students to compete on teams matching their gender identity.

The group collected about 400,000 signatures but fell short of the 546,651 needed to qualify, and vowed to try again in 2026.

“This fight is not over in California,” Lorey said. “We’ll keep pushing bills, keep showing up at CIF meetings, keep standing with girls who’ve lost spots and medals, and keep building support through our XXOnly.org campaign. If Sacramento won’t act, the people will eventually have their say.”

Republican Assemblywoman Kate Sanchez has also introduced legislation to bar transgender girls from girls’ sports, but the effort has stalled in the Democrat-controlled Legislature.

“We’ve supported legislation like Assemblywoman Kate Sanchez’s AB 89, and I testified for it at the Capitol. Democrats on the committee blocked it, and one legislator compared protecting girls’ sports to Nazi Germany. That tells you how far Sacramento is from ordinary Californians,” Lorey told the Post.

Colorado voters were also weighing Proposition 134, which was leading with 52.7% of the vote, with about 87% of ballots counted Wednesday.

The measure would require athletic teams from elementary school through college to be designated male, female or coed, with eligibility based on a student’s biological reproductive system.

Girls would still be allowed to join boys’ teams when no girls’ team is available, and the state education commissioner could take action against school districts that refuse to comply.

Protect Kids Colorado, which collected more than 168,000 signatures to qualify the measure, is also behind Proposition 135, a separate proposal to ban gender-transition surgeries for minors that was also leading.

Nadine Bridges, executive director of LGBTQ advocacy group One Colorado, argued Prop. 134 could lead officials to scrutinize girls who appear too tall or too strong.

Nebraska voters approved the Fairness for Girls constitutional amendment with 68% support.

The measure qualified for the ballot in August after organizers collected more than 200,000 signatures. It writes into the state constitution Nebraska’s existing ban on transgender athletes competing in girls’ and women’s sports from kindergarten through college.

Supporters sought to make the restriction harder for a future state Legislature to repeal.

“Washington and Colorado just showed this isn’t a red-state issue. It’s a common-sense issue. Even Governor Newsom has admitted it’s deeply unfair for boys to compete against girls,” Lorey said.

“The only thing standing between California voters and this protection is a Legislature that refuses to listen and a ballot process built to keep the people out.”