Preserving biodiversity in remaining old-growth forests is a high priority for many land managers. To this end, we inventoried the diversity, abundance, and distribution of epiphyte species in one 318-year-old, 86 m tall Picea sitchensis tree on the north coast of California. In 39 plots, we recorded species present and mean percent cover for each species. Our findings include the following: 1) 68 epiphyte species were found in this one tree; 2) epiphyte diversity increased with height; 3) lichens had the highest diversity of all epiphyte classes; and 4) mosses had the highest percent cover of all epiphyte classes. These findings highlight the capacity for old trees to serve as reservoirs of biodiversity in younger forests.