In 1892 he abandoned this field for Ecuador, Bolivia and Peru, where he continued ethnological, archaeological and historical investigations. In the first field he was in a part of his work connected with the Hemenway Archaeological Expedition and in the second worked for [Henry Villard of New York, and for the American Museum of Natural History of the same city. Bandelier has shown the falsity of various historical myths, notably in his conclusions respecting the Inca civilization of Peru.
His publications include: three studies “On the Art of War and Mode of Warfare of the Ancient Mexicans,” “On the Distribution and Tenure of Lands and the Customs with respect to Inheritance among the Ancient Mexicans,” and “On the Social Organization and Mode of Government of the Ancient Mexicans” (Harvard University, Peabody Museum of American Archaeology and Ethnology, Annual Reports, 1877, 1878, 1879); Historical Introduction to Studies among the Sedentary Indians of New Mexico, and Report on the Ruins of the Pueblo of Pecos (188i); Report of an Archaeological Tour in Mexico in 1884 (1884); Final Report of Investigations among the Indians of the South-western United Stales (1890—1892, 2 vols.); Contributions to the History of the South-western Portion of the United States carried on mainly in the years from 1880 to 1885(1890).