The Indians in California's North Coast Range obtained one of their principal foods from tanoak. In fact, the main fare of many Indian communities was salmon and tanoak acorns. The large acorns were ground, leached, and then prepared as a soup, cooked mush, or a kind of bread. After being leached, the acorns are said to have an agreeable acid taste. They also contain a comparatively large amount of oil. On this account, tanoak acorns were preferred by local Indians over all other kinds. Ground tanoak acorns have also been fed to chickens.
Tannin from tanoak bark has properties intermediate between chestnut tannin and the usual oak tannin of commerce. The extract from tanoak bark, however, furnishes the best tannage known for the production of heavy leathers. For example, it gives excellent plumping when used to tan sole or saddle leather. The superiority of tanoak bark extract is attributed to the presence of certain other acids, such as gallic and acetic, with the tannic acid. Tanoak tannin has also been used medicinally as an astringent (24).
One successful attempt to graft European chestnut (Castanea sativa) scions to tanoak stumps has been reported from southern Mendocino County.