Diary of the Trip to the Bermejo River

In Diary of the Trip to the Bermejo River (Diario del viaje al río Bermejo) Fray Francisco Morillo tells us about his trip along the banks of the Bermejo River, one of the most important in the La Plata Basin, and one of the most notable geographical features of the Gran Chaco region.
The first exploration of the river by European settlers took place in 1780, when Francisco Morillo and twenty other sailors went up their course trying to find a means of transport that the missionaries could use in their trips inland. This edition includes a preface by Pedro de Angelis.

The year of the lord of 1780 of the vulgar era, I left with the subordinate captain, Don Adrián Cornejo, of the new shipyard of the Ledesma River, distant from the city of Salta 38 leagues, and of that of Jujuy 26, in the company of 20 individuals, which was the number of this fluvial crew: in a boat of eight keels and two canoes; being our defeat until the city of Corrientes, discovering this road until today not discovered. This expedition was at cost; and costs of the said Cornejo, for having so promised to the Sovereign, except to me his Chaplain, who came without any pre pre.
We left, therefore, the shipyard mentioned, half-finished the ship, and walking along the said River of Ledesma, for the space of thirty days, we advanced only three leagues of road by the poor of its waters, and equal poverty of laborers.
On September 4 we arrived at the Jujuy River, whose course turns from S. to N, in which the Ledesma River is incorporated: being its source of a mountain range so called, to the western part; and on its margins to the part of the S, distant two leagues, is a reduction called San Ignacio de Tobas, in charge of the religious of my order; and a presidio called San Bernardo: and on the N-side, at a distance of a league, is the Fort of Our Lady of the Rosary of Ledesma, built both in the jurisdiction of Jujuy.