The flat marshland composing the estuary of the Agusan River in northeastern Mindanao is inhabited by a group of people now known as the Butuanon. The native Butuanon, however, would refer to himself rather as a "Lapaknon" or a person who lives in the swampy areas in Libertad. The people and folk historians, on the other hand, believe that they are an offshoot of Manobo populations of the Agusan Valley. The language of the Butuanon is more closely related to Cebuano than any of the Manobo tongues. In fact, the languages of Butuanon, Tausug of Jolo, and Kamayo of Bislig have a very close affinity.

       Linguistic data suggest that the Tausug moved into the Sulu archipelago from the general area of Butuan during the eleventh century, at a period of intense trade between Agusan and the Chinese, as shown by the very rich archaeological materials in the area. The Kamayo might have developed from the very early connections of Butuan with Caraga on the eastern coast of Mindanao.

       The population (24,566 NSO 1990) is at present highly urbanized with a defined Visayan culture highly influenced by the Cebuano. Much of the production of the area is in rice, coconuts, logging, fishing, and fish culture.