This report summarizes the fieldwork and preliminary lab analyses conducted during the first season of the Caves Branch Archaeological Survey project, which focused on the cave sites of Actun Lubul Ha and Franz Harder Cave,Overlook Rockshelter, and the monumental center of Deep Valley. The cave sites all show repeated use, thoughvary in the types of rituals performed and in the amount of time used. While caching activities consistent with pilgrimage are constant over time, they vary in intensity between contexts. However, the mortuary use of cavesappears to intensify significantly during the Late- to-Terminal Classic period (A.D. 700-900). These patterns maybe directly related to the apparently late founding of the minor civic-ceremonial center of Deep Valley and other settlements in the Caves Branch River Valley between A.D. 600 and 800. While subterranean sites areunquestionably important in documenting the extensive history of use of the Caves Branch River Valley, settlement data are critical to understanding the rise of local social and political complexity