Student athletes in Cherry Creek School District and Littleton Public Schools could lose the ability to play on teams matching their gender identity if Colorado voters approve Proposition 134 on Tuesday, Nov. 3.

The measure would require every school and college athletic team in the state to be designated male, female or coeducational, with participation based on biological sex. If approved by a simple majority, the law would take effect Jan. 1, 2027, according to Chalkbeat Colorado.

Colorado schools currently have varying policies on transgender athlete participation. The Colorado High School Activities Association (CHSAA), the governing body for high school sports, requires transgender students to disclose their status to their school for a confidential evaluation, the Colorado Sun reported. Schools can request, but not require, health records verifying gender identity. Families can appeal eligibility decisions to CHSAA.

Proposition 134 would end that evaluation process entirely. The state education commissioner would enforce the new policy and take action against public schools that violate it, according to the Sun. The measure includes no enforcement mechanism for private K-12 schools or colleges.

No organization or state agency tracks how many transgender students play on school sports teams in Colorado, Chalkbeat reported. The number is thought to be a very small percentage of student athletes.

Cherry Creek Schools recently hired Tanya Bond as its athletics and activities director. Bond, a Colorado native and former volleyball coach who spent more than two decades at Eaglecrest High School, has said she wants to expand opportunities so every student can find a place in CCSD athletics. Neither CCSD nor LPS has made a public statement on Proposition 134.

Erin Lee, co-founder of Protect Kids Colorado, the group that placed the measure on the ballot, told the Denver Post that girls deserve their own sports category. Lee said students could verify their biological sex through doctor's notes or cheek swabs, a form of DNA testing that can cost hundreds of dollars, according to Chalkbeat.

Opponents say the measure's vague language could subject all student athletes to invasive scrutiny. Nadine Bridges, executive director of LGBTQ advocacy group One Colorado, told Chalkbeat the measure "is written so vaguely that there aren't any boundaries, no parameters, no appeal process at all."

Chris Cook, the father of an 11-year-old transgender girl, told the Sun his family moved to Colorado from Kansas seeking more safety and respect. Cook said the measure could lead schools to single out any child who looks too tall, too strong or does not fit someone's idea of what a girl should look like.

If passed, Proposition 134 would also conflict with the Colorado Anti-Discrimination Act (CADA), which prohibits discrimination based on gender identity in public schools, the Denver Post reported. Title IX attorney Ashlyn Hare told the Post that Proposition 134 would likely supersede CADA on the question of transgender athletes, though it would not invalidate the act entirely.

The measure would change state statute, not the state constitution. That means the legislature could later amend or repeal it.

Opponents have outspent supporters by a wide margin. A coalition including One Colorado, Planned Parenthood and the American Civil Liberties Union raised a combined $1.3 million through mid-September, compared with about $152,730 raised by Protect Kids Colorado, according to state campaign finance records cited by the Sun. Colorado Newsline reported that about 60% of Protect Kids Colorado's funding came from a dark-money nonprofit also named Protect Kids Colorado.

Voters have until 7 p.m. on Nov. 3 to return ballots at a drop box or polling center, or vote in person.