A judge has dismissed a lawsuit contesting a transgender woman’s admission into a sorority at the University of Wyoming, ruling that he could not override how the private, voluntary organization defined a woman and order that she not belong.

In the lawsuit, six members of the Kappa Kappa Gamma sorority chapter challenged Artemis Langford’s admission by casting doubt on whether sorority rules allowed a transgender woman. Wyoming U.S. District Court Judge Alan Johnson, in his ruling, found that sorority bylaws don’t define who’s a woman.

The case at Wyoming’s only four-year public university drew widespread attention as transgender people fight for more acceptance in schools, athletics, workplaces and elsewhere, while others push back.