Colorado state epidemiologist Dr. Rachel Herlihy said the two were deployed to a nursing home struggling with an outbreak of COVID-19.
Herlihy appeared in a virtual briefing with Colorado Governor Jared Polis.
The new variant, which was first discovered in Britain, is thought to be more transmissible.
JARED POLIS: As many of you are aware, yesterday the Colorado State lab confirmed the first variant of COVID-19 in the United States right here in Colorado. Now to be clear that doesn't mean that Colorado is the first state that has people with the variant. In fact, it's very likely it exists in many states. Particularly the states that have more interaction with the United Kingdom in the New England and mid-Atlantic area. But I'm very proud that our state lab was the very first to detect that variant.
RACHEL HERLIHY: Our investigation and contact tracing efforts are ongoing, but at this time we are aware of one confirmed and another possible case with the B117 variant of the virus as described by Dr. Travanti. Both of these cases are Colorado National Guard personnel who were deployed to support staffing at the Good Samaritan Society nursing home in Simla, Colorado, that's in Elbert County. Their deployment at the facility began on December 23. The nursing home has an ongoing outbreak of COVID-19. Cases of COVID-19 were first identified in the facility in mid-December following routine surveillance testing in that facility.