Today’s waste landscapes derive from nineteenth-twentieth century materials extraction, processing, and disposal practices by which certain landscapes are sacrificed for the construction of others. Long term impacts of material byproducts from these industries may be understood as technofossils—new materials shaped into artifacts that will likely be preserved as geological deposits. This article explores shifts in cultural attitudes and approaches towards waste materials and landscapes by focusing on two types of extraction-based industries that create technofossils: brick, in which desired materials such as sands and clays are extracted and manipulated, and dredged sediment, in which undesirable materials, such as sands, clays, and soils, are extracted from shipping channels and stored in landfills of land. The tension between these industries reveals opportunities for rethinking linear models of materials extraction, processing, and disposal as cyclical and integrative. Historiographic, archival, and case study research are used to investigate these industries. Speculative mapping and a design research studio explore these material legacies, and their potential ecological, socio-economic, and cultural values.