Two Mountain West states are part of a dozen across the country that allow people to select non-binary gender on legal documents.
Colorado residents, who do not identify as male or female, will be able to choose "X" as their gender on driver's licenses starting on Nov. 30.
"It's really important that Colorado is now allowing another opportunity for male, female and non-binary -- people who identify as neither male or female -- to also have an identity document who matches who they are," said Daniel Ramos, executive director of One Colorado, an LGBTQ advocacy organization.
Utah also allows residents to choose a third option on legal documents, but those who wish to change their gender status must get approval from a judge. A bill that would update the state's current gender identity law will be introduced for a second time to add the non-binary option.
"(It's a) very important bill for the transgender and intersex community," said Sue Robbins, chair of the board of directors for the Utah Pride Center. "It defines things that were guaranteed, our right to be able to self-declare and have our legal documentation match that."
If the bill passes, it could take effect as early as next May.