There are many blended populations. I think it is a mistake to view the term "Melungeon" as designating either a distinct ethnic group or cultural population, or to apply the term to all tri-racial populations in the USA. I think it s probably best understood, at this point in time as a regional term that is nebulous in what it signifies, even within the region (upper and middle upper south, ranging from the Piedmont area of North Carolina, the southwest Piedmont of Virginia, and the southern Appalachians,) although it does appear to have been most often used, locally, within the region, to signify people of tri-racial ancestry, or possibly bi-racial ancestry of Caucasian-Native American.