A year-long continuous pitfall trapping program in 8 habitats at the Savannah River Site on South Carolina's coastal plain yielded over 4200 individual Opiliones, and the resulting data set provides a fine-grained description of Opiliones faunistics, habitat distribution, and phenology in southeastern North America, where Opiliones biology has been neglected. The 9 species reported from the site include a new state record (Vonones sayi), a rarely reported species (Bishopella laciniosa), and a common species that was undescribed at the time of the study (Hadrobunus fusiformis). All species abundant enough to examine seem to be univoltine and to reproduce in the warm season (adults mostly present in autumn), but species varied greatly in seasonality and duration of the peak adult sample period and in their habitat distribution. Leiobunum bimaculatum preferred xeric sites, H. fusiformis was widely distributed across habitats, and the other species were generally more abundant in more mesic habitats. Richness estimation showed that the ground-accessible Opiliones fauna was adequately sampled by this pitfall regime.