The Common Gallinule breeds in scattered locations throughout the eastern U.S. and is a year-round resident of Florida, the Gulf Coast, and the south Atlantic Coast (Bannor and Kiviat 2002). Western populations of this species are year-round residents, occurring along the coast of California, Arizona, New Mexico, and Texas (Sibley 2014). In Montana, the Common Gallinule has a single record and is considered an accidental species (Montana Bird Distribution Committee 2012).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.