Zinapecuaro, Michoacan, Mexican Obsidian Artifacts at Piedras Marcadas Pueblo's Sixteenth Century Battlefield (LA 290), Middle Rio Grande Valley, New Mexico

Direct evidence of the presence of the Mexican indigenous soldiers that accompanied the Coronado entrada into what is now the United States has remained invisible. Dolan and Shackley's recent examination of the presence of four obsidian blades produced from obsidian sources in the Sierra de Pachuca in Hidalgo state of Mexico, was the first intensive examination of artifacts that could directly signal the presence of Mexican indigenous soldiers north of Mexico, although only two had adequate provenience. Since then, three obsidian artifacts, produced from the Zinapecuaro obsidian source from Michoacan state of Mexico were recovered and determined to be from that source by XRF at Piedras Marcadas Pueblo in the Middle Rio Grande valley in Albuquerque, New Mexico, besieged by Coronado and his soldiers in the winter of AD 1540-1541. This is the best direct evidence of artifacts transported by the "indios amigos" to the Middle Rio Grande valley.