Abstract
Bedrock mortars were an integral part of intensive acorn economies in Native California and are a prominent feature of the Late Holocene archaeological record of the Sierra Nevada. Construction of these milling features also indicates a long-term investment in the landscape. Ethnographic evidence suggests the importance of local acorn crops and other resources led to ownership and defense of property and resource rights in many areas. Through a combination of time-sensitive projectile points and obsidian hydration dating, we show that bedrock mortars became widely used in the Sierra Nevada after 1300 cal BP, and that this was coincident with the arrival of the bow and arrow to the region. When and where bedrock milling features occur provides evidence for evolving territorial behavior during the Late Holocene and further insights into how prehistoric Californians leveraged technology and behavioral changes to solve the difficult problem of making a back-loaded resource both palatable and profitable.