Food storage is a crucial adaptation for hunter-gatherers who face seasonal resource shortfalls, but the extra time that hunter-gatherer s must spend accumulating food surpluses has the potential to conflict with the time they need for other activities during seasons of abundance. Since the activities that conflict with storage may be different for women and men, it is important to consider which gender is responsible for storage. We argue that when women perform most storage tasks, the tradeoff between foraging and childcare is likely to shape storage behavior, particularly the decision of which foods to store. Our analysis of storage food preferences among the prehistoric hunter-gatherers of California’s Sierra Nevada suggests that women altered their storage strategy during the late Holocene when the shift to a semi-sedentary settlement system increased the conflict they faced between foraging and providing childcare. The adoption of an acorn-based storage economy during this period allowed women to minimize the time they spent foraging away from their residential bases, so they could better accommodate their childcare needs. This study demonstrates the utility of considering issues beyond the rate of caloric return from foraging to develop more complete models of hunter-gatherer behavior and explanations of the archaeological record.