Río Biobío
While historian José Bengoa concludes that Inca troops apparently never crossed Bío Bío River, chronicler Diego de Rosales gives an account of the Incas crossing the river going south all the way to La Imperial and returning north through Tucapel along the coast. In Osvaldo Silva's reconstruction of the events leading to the battle of the Maule the Incas may have reached as far south as the Concepción area next to Bío Bío River in the early 1530s before returning north., However, no inca material has been found south of Bio Bio River.