CBAS is a research program focusing on the rich cultural history of Maya populations who once inhabited the Caves Branch River and Roaring Creek Valleys and the surrounding uplands. Located approximately 20 miles southeast of the city of Belmopan (Belize’s capital) in Central Belize, the lush river valleys are framed by jungle growing on the steep karst foothills of the Maya mountains. The strongest evidence of early human activity in the area dates to the Middle-Late Preclassic periods (around 300 BC) and is in the form of ritual offerings found in the many caves riddling the limestone cliffs. Our recent work in the Caves Branch Rockshelter uncovered an Archaic spearpoint dating to 2500 – 1900 BC, which is the first evidence that the arrival of humans in the valley may have been even earlier. Rituals were performed in many of the caves in the area through the Preclassic and Classic periods, though at present there is little other evidence of settlement until, quite suddenly, during the Middle Classic period (around AD 500) the monumental centers of Yaxbe, Deep Valley, and Tipan Chen Uitz were built, complete with elite residential compounds and large ceremonial structures around open public plazas. Surveys of the surrounding countryside show increased settlement at this time as well as the integration of multiple sites – Tipan, Yaxbe, and Cahal Uitz Na – via a network of ancient roads (sacbeob). But, soon after this florescence, the area was abandoned. By the end of the Classic period (AD 900), there is a startling absence of activity in these centers, in the countryside, and in the caves.