At the present time, the Ajumawi people living in the Fall River Valley southeast of Mount Shasta use a yellow mushroom with hallucinogenic properties (A. pantherina) for religious purposes, and have done so at least since the early part of the twentieth century. If this mushroom was used prehistorically in northern California, as is suggested here, the use of hallucinogenic mushrooms in North America may have been more widespread than previously believed.