The paper explores the potential for adaptive mitigation at the Montezuma Wildlife Refuge, Seneca Falls, NY, USA, and surrounds, focusing on landscapes along the historic Erie Canal that inadvertently lowered the water table and shrunk adjacent wetlands. Now the Erie Canal National Heritage Corridor (ECNHC), Montezuma, NY, USA, the canal, and surrounds lack a clear identity but have the potential to be repurposed as green infrastructure to support climate mitigation through the application of natural climate solutions, namely reforestation. Reforestation has been shown to produce the highest potential performance for carbon sequestration, along with a multitude of co-benefits. However, most studies assessing capacity for climate mitigation using nature-based approaches operate at a high level via remote data and do not test hypotheses at smaller scales that require groundtruthing data, parcel-by parcel approaches, and an understanding of landowner values. The initial research question is: can landscape architecture design research contribute to a higher performance of secondary forests and non-productive farmland (fallow lands) for carbon sequestration, while at the same time activating economic territories and improving their landscape qualities? Comparative cartographies are developed to assess secondary forests, including past and future projections. Fallow lands are examined through mapping at various scales, fieldwork, and informal interviews. We find that farmland along the canal has been abandoned over time due to conditions that make farming difficult, such as periodic flooding, ponding of water due to poorly drained soils, and steep drumlin slopes. These same conditions have contributed to a landscape armature—an assemblage of landscapes including the old canal, barge canal and associated heritage landscapes, abandoned farmlands, and existing forests and wetlands. Secondary forests already existing in the area are high performing in relation to carbon sequestration but may lack climate resilience due to threats such as the emerald ash borer (EAB). Design intervention can help support enhanced sequestration, resilience, and adaptation by introducing unique tree plantings in the form of groves and hedgerows. Sustainability is approached by integrating quantifiable performances of secondary forests with projections of spatial, ecological, and cultural values and the continuing monitoring and management of forests over time. The aim is to build a method to test these lands with designs for tree plantings that reveal their potential for increased carbon sequestration, habitat connectivity, and enriched landscape identity.