Calamaco appears in approximately 120,000 historic records, 11,000 tree persons, and 500 uploaded memories, on FamilySearch, one of the largest genealogical records providers worldwide. The surname is most often found in Mexico, with fewer in the United States as well as Guatemala. A small number are also found in Portugal. The origin of this surname is not known, but there is limited usage as a noun describing a woolen garment, or in another case, kidney beans. This group project funds free Y-37 DNA tests for all Calamaco males, pending application approval. Please refer any interested person to email the group administrator.