A six-year-old transgender girl has won the right to use the girls restroom at her school in Colorado.
The decision was made by the Colorado Civil Rights Division on Sunday that the Fountain-Fort Carson School District created an unnecessarily hostile situation for Coy Mathis by not allowing her to use the female bathroom.
Transgender advocates are hailing the decision as a major step forward for transgender rights.
By not allowing Coy to use the girls' restroom, the Eagleside Elementary School in Fountain 'creates an environment rife with harassment,' Steven Chavez, the division director, wrote in the decision.
The Denver Post reported that the New York-based Transgender Legal Defense and Education Fund will be holding a news conference Monday to explain the decision affecting Coy Mathis.
Coy Mathis, who was born male but has identified as female since the age of four, was barred from using the girls' restroom at Eagleside Elementary School in Fountain, Colorado in December.
Mathis' parents, Kathryn and Jeremy Mathis, filed a complaint through the Transgender Legal Defense and Education Fund in February.
Prior to the complaint, the first-grader, who dresses as a girl and is recognized as female on her passport and state-issued ID, had experienced no issue using the girls bathrooms.
'She would use the girls restrooms, she would be called a girl, she would go in the girls lines,' Mrs Mathis told Katie Couric in an episode of Katie dedicated to the issue.
But a year after making the transition at school, the Fountain-Fort Carson School District informed Coy's parents that she would be barred from using the girl's restrooms after the winter break.
Explaining the chain of events, Mr Mathis said: 'We got a call one evening, it was the principal and he said he wanted to set up a meeting with us to discuss options for Coy's future use of the restroom.
'It came out that Coy was no longer going to be able to use the girl's restroom and they were going to require her to be using the boy's room or the staff bathroom or the bathroom for the sick children.
'We didn't know why... we had no idea where this was coming from.'
After receiving the news, the couple, who have five children under eight, took all of their children out of Eagleside Elementary School and filed a complaint with the state's civil rights division.
But W Kelly Dude, the lawyer for Fountain-Fort Carson School District 8, told CNN that the school 'took into account not only Coy but other students in the building, their parents, and the future impact a boy with male genitals using a girls' bathroom would have as Coy grew older...
'I'm certain you can appreciate that as Coy grows older and his male genitals develop along with the rest of his body, at least some parents and students are likely to become uncomfortable with his continued use of the girls' restroom,' he added.
The Mathis' case was the first to challenge restrictions on a transgender person’s bathroom use under Colorado’s anti-discrimination laws.
Mrs Mathis said that Coy was just 18-months-old when she started being drawn towards 'everything girl'.