Recent archaeological work suggests that people began moving away from Crystal River in Phase 3, which probably began between around AD 500 and 600 and lasted until sometime between AD 650 and 750, during the Late Woodland Period. Nevertheless, the site seems to have continued to serve as a ceremonial center. The village contracted to the area north of Mound A, which was expanded during this interval; perhaps the continuing presence represents a caretaker population or a compound occupied by a leader and his or her family. Some of the former residents of Crystal River may have moved the short distance downstream to Roberts Island, where settlement was initiated in this interval. Shifts in settlement such as this abandonment and collapse are typical of the Gulf Coast at this time, and may be at least in part a response to a more variable climate and lowered sea level associated with the interval known as the Vandal Minimum.