Coloradan Trangendered Girl Fighting to Use Girls' Bathroom at School

School district worried impact on other students and teachers

(CNN) -- Just like she did during the first half of the school year, first-grader Coy Mathis wants to use the girls' restroom at her Colorado elementary school. But school officials won't let her.

The reason? Coy is transgendered, born with male sex organs but a child who identifies herself as female.

She dressed as a girl for most of last year. And her passport and state-issued identification recognize her as female.

In December, the Fountain-Fort Carson School District informed Coy's parents that Coy would be barred from using the girls' restrooms at Eagleside Elementary in Fountain after winter break.