This IBA encompasses various state-owned lands along the Peshtigo River below the town of Peshtigo, including the Peshtigo Harbor Unit of the Green Bay West Shores State Wildlife Area, Bloch Oxbow and Pines State Natural Area, and other state gift lands. The site contains some of the most significant riparian and wetland habitats in the Green Bay ecosystem, including extensive tracts of floodplain forest (at the northeastern edge of its range in the state), sedge meadow, emergent marsh, and sandy uplands featuring northern dry-mesic forest and semi-open grasslands.
A long list of priority breeding birds includes red-shouldered hawk, osprey, northern harrier, American bittern, Forster’s tern, golden-winged warbler, grasshopper sparrow, field sparrow, bobolink, and eastern meadowlark. Yellow rails are known from the site. Colonial waterbirds such as Caspian tern and great egret often forage here