For thousands of years, the California landscape (and riparian areas in particular) has been tended and its resources sustainably harvested by its inhabitants. Prior to Euro-American settlement, California Native Americans manipulated the natural resources, particularly plant resources, to meet long-term cultural needs. Our hypothesis is that the floodplain biodiversity and native fish productivity benefited from burning and other traditional management practices utilized by the Plains Miwok and other Native Californians for thousands of years. These practices may have enhanced floodplain rearing habitats, thereby increasing fish growth and reducing fish mortality. We support our argument with ethnographic data, traditional knowledge and archaeological fish faunal remains to reconstruct the landscape of the lower Cosumnes River watershed prior to Euro-American settlement and alteration. The historical reconstruction proposed here will illustrate, within the limitations of the data, how past indigenous traditional management practices influenced both vegetation patterns and probably fish species distributions in the Lower Cosumnes River watershed. These practices may have enhanced floodplain rearing habitats, thereby increasing fish growth and reducing fish mortality. Traditional resource management has been demonstrated to do the following: