Combining Indigenous traditional ecological knowledge (TEK) with scientific research holds promise for more effectively meeting community objectives for the conservation of cultural forest resources. Our study focuses on predicting the abundance of western redcedar trees (Thuja plicata) within the traditional territories of five Indigenous Nations that are part of the Nnwaolas Council in British Columbia, Canada. Indigenous people in this region use western redcedar extensively for cultural practices, such as carving dugout canoes, totem poles, and traditional buildings. However, after more than a century of industrial logging, the abundance of redcedar suitable for these types of practices is in decline and no longer reflects past baseline conditions. We assess how using TEK from interviews with Indigenous carvers refines predictions of resource abundance compared to using only conventional field surveys. Our findings reveal that western redcedar trees suitable for traditional carving are generally rare, and that some important growth forms, such as those associated with carving community canoes, are nearly extirpated from the landscape. We demonstrate a useful application of TEK in conservation planning and highlight concerns about the impact of industrial forestry on culturally important trees.