Renewed archaeological investigation at Unai Bapot in Saipan refines the documentation of chronological change during the earliest period of human occupation of the Mariana Islands. First site use was in the range of 1600 to 1420 BC, and site abandonment occurred shortly after AD 1670. In more than 2 m of continuous stratigraphy, abundant examples of pottery occur in stratigraphic order in seven distinct occupation layers with minor internal variations. Other artifacts include shell and coral pendants, polished chert and shell adzes, various types of flaked stones and shells, fishhooks, and other objects. Faunal materials are almost entirely shellfish remains, and changes in shellfish taxa reflect a drop in sea level and associated habitat transformation in the first millennium BC. The new data support a refined substantive evaluation of the role of early Marianas settlement as the first human colonization in Remote Oceania.