Ethnographic interviews and historical literature reviews provide evidence that the nine ethno-linguistic groups inhabiting the foothill region of the western slope of the Sierra Nevada relied on a variety of plants and animals from chaparral communities to meet their material needs and deliberately burned the chaparral to maximize its ability to produce useful products. The reasons for burning in chaparral are grouped into six ecologically-based categories, each relying on a known response to fire of the chaparral flora, community, or landscape. The densities of people in the region were high, and villages needed large quantities of chaparral-derived materials with specific qualities to make many cultural objects. Because the majority of chaparral-occurring species used as cultural resources by Native groups required frequent fire in order to exist in sufficient quantity, or to be useful, fires caused by lightning strikes were likely insufficient to meet needs. The authors posit that tribes employed intentional burning to expand the availability, abundance, and diversity of plant materials necessary for foods, medicines, and critical technologies and that they collected plants and animals from across a mosaic of periodically burned chaparral stands at different stages of ecological succession. Overall the evidence suggests that the burning of chaparral, as a major strategy for economic intensification and extensification, altered the natural fire regimes of the foothills by expanding the burn season, shortening the fire-return interval in specific areas, and enhancing the abundance and density of species that suited specific cultural objectives.