Small elevational changes in the undulating topography near Cascadilla Creek result in significant changes in hydrology and vegetation. Upland forest, swamp forest, shrub swamp, small patches of rich fen, wet meadow and marsh are all found here. Beech-maple forest is prevalent on the low rises with cucumber magnolia (Magnolia acuminata), red oak (Quercus rubra), white pine (Pinus strobus) and hemlock (Tsuga canadensis) present.
Hemlock, red maple (Acer rubrum) and yellow birch (Betula alleghaniensis) dominate the swamp forest. American elm (Ulmus americana), black ash (Fraxinus nigra), swamp buckthorn (Rhamnus alnifolia), black chokeberry (Aronia melanocarpa), cranberry viburnum (Viburnum trilobum) and swamp gooseberry (Ribes hirtellum) are other characteristic species. Speckled alder (Alnus incana ssp. rugosa) dominates in the shrub swamp.
In the wet meadows and marsh, characteristic species include: cinnamon fern (Osmunda cinnamomea), Joe-Pye weed (Eupatorium maculatum), swamp aster (Aster puniceus), common bulrush (Scirpus atrovirens), swamp milkweed (Asclepias incarnata) and various sedges (Carex spp.).