Ethnohistory is the study of ethnographic cultures and indigenous customs by examining historical records. It is also the study of the history of various ethnic groups that may or may not exist today. Ethnohistory uses both historical and ethnographic data as its foundation. Its historical methods and materials go beyond the standard use of documents and manuscripts. Practitioners recognize the utility of such source material as maps, music, paintings, photography, folklore, oral tradition, site exploration, archaeological materials, museum collections, enduring customs, language, and place names.

Answer this question, if possible (if impossible, reply "unanswerable"): What does ethnohistory use both historical and ethnographic data as?
its foundation