At Cornell, Barreiro was founding editor of Native Americas Journal (1995–2002). In 2003-2006, he redesigned and was Senior editor of Indian Country Today. He is also the editor of Indian Roots of American Democracy, (1988), and the ethnographical testimony Panchito: Mountain Cacique (2001). Barreiro's first novel, published in 1993, was The Indian Chronicles, a pseudo-journal of the life of Diego Colon, a 12-year-old Taino whom Christopher Columbus takes with him to Spain in 1493, and who later returns to the Americas, where he supports the Taino resistance led by Guarocuya. A recent book, America is Indian Country, canvasses issues and personalities in Indian Country. Barreiro is also editor of the announced book, Thinking in Indian: A John Mohawk Reader.