We studied the influence of local site characteristics on the abundance of Equisetum scirpoides, a regionally rare, circumboreal species, at five sites in the Deerfield River watershed of Massachusetts, near the southern edge of its range. Equisetum scirpoides was most abundant on north- to northeast-facing, steep slopes (22–34°), with low total basal area (TBA) and small stem size. While E. scirpoides was always found in association with Tsuga canadensis, plots with high-density E. scirpoides were associated with lower Tsuga TBA than “low density/absent” plots. Average Tsuga and deciduous stem diameter at breast height within “high density” plots was significantly lower than in “low density/absent” plots. Our results suggest that E. scirpoides is unlikely to occur on south-facing slopes and, where it occurs on north-facing slopes, it requires low deciduous canopy cover and frequent disturbance, which exposes mineral soil. Equisetum scirpoides was absent from several similar habitats (i.e., with northerly aspect, steep slopes, clay substrate, Tsuga canopy, and massive bank failure) within the study watershed, suggesting that it has low dispersal capability at that scale.