the agusan valley was settled by a variety of cultural communities like the manobos, mamanwas and higaonons. archeological excavations in the lower agusan valley plains have uncovered evidence of strong relationships between the region and the southeast asian states. a golden image of javan-indian design unearthed in the 1920s and molten jars uncovered in prosperidad are indications that the region had commercial and cultural ties with the coast.