Poinsettia was once a cinnabar mine. Reportedly, the mine was worked from 1929 to WWII, but information is hard to find on it and no production was recorded. It is doubtful much cinnabar was ever mined here. Cinnabar is a primary ore for mercury, which is important in the gold recovery process.
When we first visited the site back in 2002, we found a blacksmith shop with a forge. Unfortunately, sometime since then, the forge and building are gone. A few cabins do remain, however, and the place makes a neat spot to base camp from and explore the surrounding area. Please use Backcountry Cabin Etiquette when staying at the cabins.