For those keeping tabs on active and nonactive U.S. gem deposits, add Yogo Gulch, Montana, to the endangered list.

Yogo, known for its deep blue sapphires, has been mined since the late 1800s. But according to numerous reports from Montana locals, the eastern side of Yogo Gulch, mined recently by Vortex (formerly Yogo Creek), is no longer worked, and some have put this gem deposit on the closed list.

On the other side of the gulch, the Kunisaki Mine is reportedly still a viable deposit, but some say it’s quiet and that there is no mining activity anywhere in the gulch. That means we won’t be seeing anything new for at least several years. And those with the last rough and cut from the eastern side say we’ll never see anything new. Time will tell.