The Apiká were a warrior tribe of the Tapajós River Basin and were greatly feared. According to Menéndez (1981, 85), the Apiaká's neighbors were the Bacuri and Tapanhuna on the Rio Arinos and the Oropia, Bororo, Cauairas, and Sitikawa on the upper Rio Juruena. In the nineteenth century travelers using the Arinos-Juruena-Tapajós route, which linked the centers of Cuiabá and Belém, developed peaceful relations with the Apiaká, exchanging products with them and hiring them as guides and paddlers for some of their trips. According to Koch-Grünberg, during the nineteenth and twentieth centuries the Apiaká constituted part of the labor force in extractive occupations. They worked as crew members, porters, fishermen, hunters, or rubber tappers, combining their traditional way of life with modern life. According to oral Apiaká tradition, after they were massacred in the early twentieth century, it was impossible for the survivors to maintain their traditional tribal way of life. From then on, they mixed with people of other ethnic origins: the Kokama, Kayabí, Mundurucu, Maué, Parecí, pacified Indians, and others.