Their traditions hold that they arrived from the east or southeast, coming down the Sebe River to the Ogowe, and thence to the Doumé rapids. They made canoes of okoumé, and sold slave to the Okandé, receiving European products such as guns and cloth in exchange. The SHO established a post at Lastoursville and engaged the Adouma in trade for rubber, ivory, and ebony.
During the 1970s and 80s, many Adouma moved down the Ogowe, towards Port-Gentil.
David E. Gardinier, Historical Dictionary of Gabon, 2nd ed. (The Scarecrow Press, 1994) pp. 34–35