Dr. Rivaya-Martínez specializes in the history of the indigenous peoples of the U.S. Southwest and the Great Plains during the eighteenth and nineteenth centuries. His training in anthropology and history, along with his ability to read Spanish, French, and English, permit him to approach the subject with a broad perspective. He uses the ethnohistorical method, incorporating ethnographic, archaeological, linguistic, and environmental evidence, as well as interviews with contemporary consultants, into his analyses of the documentary record and his interpretations of the past. He has conducted extensive archival research in Mexico, Spain, France, and the United States, accessing a massive corpus of non-English-language original sources, some previously untapped. Dr. Rivaya-Martínez uses qualitative and quantitative analyses to cement his theories, paying attention to indigenous voices and perspectives from the past and from the present. So far, his scholarship has focused primarily on the Comanches, whose actions influenced decisively the history of a vast expanse on both sides of the Rio Grande. He has conducted his research in close contact with members of the Comanche Nation of Oklahoma. His future scholarship will retain a multidisciplinary and cross-cultural approach.