Allegheny Portage Railroad National Historic Site is mostly forested. Typically, these are deciduous forests, dominated by tall, broadleaf trees. Oak, black cherry, maple, beech and birch predominate interspersed with pine and hemlock. The understory includes saplings of various tree species, intermediate tree species and shrubs such as witch hazel, spicebush or blackberry. Some areas of coniferous (evergreen) forest can be found within the park. Often, these coniferous forests were planted with pine or spruce species.