Southern Illinois mined lands were investigated to identify wetland-scale habitat parameters influencing the presence of a habitat limited species, the Least Bittern (Ixobrychus exilis). Total area (ha), open water area (ha), robust emergent (REM) area (ha), percent REM coverage, REM-open water edge length (m), edge:REM cover index and water depth parameters were measured at 35 wetlands (mean = 5.51 ha; range = 0.13–39.7 ha) to develop one- and two-regressor logistic regression models best explaining Least Bittern wetland use. Logistic regression models using open-water area or open-water area edge index regressors ranked highest among candidate models, which distinguished our results from those obtained in previous studies. These data suggest that human-created basins supporting at least semi-permanently flooded robust emergent cover, ample expanses (>8 ha) of open water and high emergent edge lengths relative to flooded REM area may consistently meet breeding season requisites of Least Bitterns. Further work to validate or refine this profile of Least Bittern habitat may benefit efforts to enhance pre-existing wetland resources or create new ones.