ARAGUAYA, ARAGUAY or Araguia, a river of Brazil and principal affluent of the Tocantins, rising in the Serra do Cayap6, where it is known as the Rio Grande, and flowing in a north by east direction to a junction with the Tocantins at Sao Joao do Araguaya, or Sao Joao das Duas Barras.
Its principal affluent is the Rio das Mortes, which rises in the Serra de Sao Jeronymo, near Cuyaba, Matto Grosso, and is utilized by boatmen going to Para.
The boundary line with Piauhy follows one of these ranges, the Serra de Ibiapaba, which unites with another range on the southern boundary of the state, known as the Serra do Araripe.
The leader in this movement was a really remarkable man, Miguel Jose Serra (known as Junipero Serra, 1713-1784), a friar of very great ability, purest piety, and tireless zeal.
The older historian of the state was Francisco Palou, a Franciscan, the friend and biographer of Serra; his " Noticias de la Nueva California " (Mexico, 1857, in the Doc. Hist.