The Rare Plant Occurrences geodatabase is an element occurrence data system with about 10,000 records of rare plant observations on the 6 northernmost California Channel Islands. It is a live database created with the purpose of bringing together in one space all discoverable historic and current information on the localities of about 180 rare and sensitive plants of the northern Channel Islands, California. The list of taxa was developed from agency databases, supplemented with a 1-day workshop with area botanists in 1993; the list has been updated as new information emerges. Data records range from the late 1880s to 2019, including information from herbarium labels, published and unpublished literature, agency files, botanist field notes, incidental observations and results of targeted surveys for individual taxa. The data come from authoritative sources, but the records are of varying quality, related to the nature of the original observation. Consequently, each record contains metadata about the data source and accuracy, as well as the observation itself. The database was initiated in 1994, by Kathryn McEachern, U.S. Geological Survey (USGS) Research Ecologist, and collaborators at Channel Islands National Park and the Santa Barbara Botanic Garden. It is maintained at the co-located offices of the USGS, Western Ecological Research Center, Channel Islands Field Station and Channel Islands National Park in Ventura, California.