The herbarium of the California Academy of Sciences contains over 1.5 million mounted botanical specimens from around the world. It is the sixth largest herbarium in the United States and the largest in western North America. The specimens stored in the herbarium are a permanent, documented record of the plants of the world and are the basis for much botanical information and research. In addition to significant usage by systematic botanists, the herbarium is also an invaluable resource for foresters, agricultural agents, customs officials, land-use planners and public health authorities. The herbarium serves as a starting point for such activities as identification of poisonous plants, documentation of the host plants of potentially destructive insects, and establishment of the geographic sources and habitat requirements of noxious weeds. In order to serve all of the above demands, the herbarium needs to have an efficient system for storage and retrieval of the mounted specimens. The current project will upgrade the compact storage elements of the herbarium to make the specimens more readily accessible to both herbarium staff and visitors.