Sax Zim Bog's unique combinations of many diverse boreal forest habitats make it an ideal choice for birds, both migratory and breeding species. There is a mix of lowland spruce, tamarack, and northern white cedar bog. Norway pine, white spruce, aspen, birch, balsam, and jack pine are found in the upland. Level to gently rolling topography is characteristic of this region. The largest landform is a lake plain. Soils include large areas of peat over both fine-textured and sandy lacustrine deposits. Sedge meadows, lowland brush and hayfields are also found here. There are stemless lady slippers and other species of bog vegetation such as sundew, pitcher plant, leatherleaf and bog birch.
Long known among serious birders as THE place to find northern owls and other boreal birds, the Sax Zim Bog Important Bird Area is home to a unique array of species and habitats not found in other parts of the United States. The Sax Zim Bog has a bird list of over 240 species including northern rarities such as Great Gray Owl, Boreal Owl and Northern Hawk-Owl. Over 450 Great Grays were counted in one weekend in January 2005.
Other bog specialists include Black-backed Woodpecker, Boreal Chickadee, Yellow-bellied Flycatcher and Connecticut Warbler.
Other wildlife native to the area include black bear, moose, beaver, deer, pine martens and timber wolves.