John Muir National Historic Site represents an island of protected parkland in the midst of an urbanizing landscape. The park contains over 280 native and nonnative vascular plants and unique vegetation communities including chaparral and oak woodlands representative of what the region may have looked like at the time of John Muir in the mid- to late-1800s (Jepsen and Murdock 2002). The diversity and abundance of nectar and host plants suggests that Mt. Wanda may also be home to a rich array of Lepidoptera (butterflies and moths). Lepidoptera represent a taxonomic group that is largely understudied. The goal of this inventory was to identify as many moth and butterfly species as possible within the limited parameters of time, equipment and expertise available at John Muir National Historical Site (JOMU).