ALTO SOLIMÕES, APOSTOLIC PREFECTURE OF. — Located in northwestern Brazil between the southern borders of Colombia and the eastern borders of Peru; to the east it borders the municipality of Fonte Bôa, to the south with the Brazilian territory of Acre. The region is covered by an immense equatorial forest, slightly uneven in places, traversed by numerous and wide watercourses, lakes, and lagoons, between 2° 45’ - 7° 16’ 55” S latitude and between 63° 7’ - 73° 47’ 45” W longitude (Greenwich). The climate is hot and humid, generating marsh fevers. The apostolic prefecture was erected on May 23, 1910, detached from the territory of the diocese of Amazonas or Manaos (Brazil), and entrusted to the Capuchins of the Umbrian province.
The total population amounts (official census of 1939) to 24,000 inhabitants, almost all Indians of Tucana stock and Gyra language, related to Tupy, and almost all Catholic (1,750 unbaptized). According to the description made by Fr. Fedele da Alviano (early 1934), they form 391 families scattered in 208 huts along various rivers.
Ten priests with one Capuchin brother, assisted by five Capuchin tertiary sisters (on mission since 1927, coming from the diocese of Fortaleza, where they were founded in 1904), attend to the three quasi-parishes: St. Paul of Olivenca (founded in 1759) with the secondary stations of Belém, St. Rita, and Amaturá; Benjamin Constant or Esperança (founded in 1930) with Tabatinga, Remate de Males, Aramassa, and Aruriá; St. Peter of Villanova of Tonantins (founded in 1934) with St. Anthony of Iça and Tonantins Velho. The sisters particularly attend to the two stations of St. Paul and B. Constant. There is a small seminary at St. Paul, and in the main localities the foundations of Catholic Action for youth have been laid.