Iowa · MigratoryRail (Virginia rail & sora)

Iowa DNR publishes no rail-specific hunting-zone map (the season is statewide), but the state's real marsh-habitat geography draws a clear line matching the sibling woodcock/gray-partridge records' north-vs-south Iowa pattern, here running north-central/northwest instead: the Des Moines Lobe, Iowa's most recently glaciated landform (12,000-14,000 years ago) and the only part of the state with substantial pothole-marsh density, is described by independent ecological sourcing as Iowa's "duck factory" and is where essentially all of the state's rail-supporting marsh habitat concentrates. A peer-reviewed breeding-marsh-bird study out of Iowa State University (Vanausdall, Dinsmore & Chapman, PLOS ONE 2020, call-broadcast surveys 2016-2017) surveyed 30 shallow lakes across exactly 12 counties -- Buena Vista, Calhoun, Cerro Gordo, Clay, Dickinson, Emmet, Hancock, Palo Alto, Pocahontas, Winnebago, Worth, and Wright -- all within this same Des Moines Lobe footprint, and found Virginia Rail densities highest in restored shallow lakes. The federal Iowa Wetland Management District (75 Waterfowl Production Areas across 18 counties, also concentrated in this same north-central region) independently names Virginia Rail among the confirmed nesting species at Union Slough NWR, Kossuth Co, in the heart of the same footprint.