Land After Technology: Collective Memory and the New York City Water Supply examines the consequences ¬of infrastructure development and management over the second half of the twentieth century. I argue that New York City’s rural watershed emerged as a place through the process of contesting, inhabiting, and managing this region, rather than just through the construction of reservoirs and aqueducts. These engineering projects created a network of reservoirs which capture surface water and direct it to New York City, but the ongoing negotiations of daily life in the region is what made it into a distinctive place—the watershed. I highlight the role of collective memories about the watershed’s past. From the affective labor of remembering inundated places to the quotidian tasks of interacting with environmental protection bureaucracies, I argue that collective memories and place meanings in this region shaped the contours and possibilities of a distinct model of participatory governance and collaborative watershed management. When watershed residents expressed grief for lost places, nostalgia for times gone, and resentment towards New York City, they grounded anxieties about changes in rural life in the second half of the twentieth century in terms of the places submerged for the city’s reservoirs. I tell this story through scrapbooks and ephemera, local history materials, court testimony, bureaucratic documents in state and municipal archives, and ethnographic interviews.