"A Colorado school district discriminated against a transgender first grader when it refused to let her use the girl’s bathroom..."

"... the state’s civil rights division has determined, a decision gay and transgender advocates say will have an indelible impact on how such cases are handled in the future."

Telling Coy [Mathis] “that she must disregard her identity while performing one of the most essential human functions constitutes severe and pervasive treatment, and creates an environment that is objectively and subjectively hostile, intimidating or offensive,” Steven Chavez, the division director, wrote in the decision....

It was clear, the state said, that Coy had completely integrated into society as a girl — wearing girls’ clothing, standing in the girls’ line at school and choosing to play with girls.

But the state’s ruling went even further, saying that evolving research on transgender development showed that “compartmentalizing a child as a boy or a girl solely based on their visible anatomy, is a simplistic approach to a difficult and complex issue.”