 Indigenous populations thrived on salmon and other fish, deer, tule elk, acorns, pine nuts, small game, mollusks, grass seed, berries, insects, edible plants, bulbs, and roots, making it possible to sustain a subsistence hunter-gatherer economy without agriculture as known by Europeans but by means of sophisticated management of landscapes and vegetation with regular, controlled low-intensity burning.This tradition of landscape management through fire ecology maintained acorn groves and other food sources, which along with knowledge of migratory herds such as elk and anadromous runs of salmon in the rivers, supported villages, small tribes, and extended family groups.A dietary staple for most Indigenous populations in interior California was acorns, which were dried, shelled, ground to flour, soaked in water to leach out their tannin, and cooked.