The California Natural Diversity Database (CNDDB) is a "natural heritage program" and is part of a nationwide network of similar programs overseen by NatureServe (formerly part of The Nature Conservancy). All natural heritage programs provide location and natural history information on special status plants, animals, and natural communities to the public, other agencies, and conservation ... organizations. The data help drive conservation decisions, aid in the environmental review of projects and land use changes, and provide baseline data helpful in recovering endangered species and for research projects.
The goal of the CNDDB is to provide the most current information available on the state's most imperiled elements of natural diversity and to provide tools to analyze these data. For more detailed information on the CNDDB, read this article from Fremontia, a publication of the California Native Plant Society. The CNDDB concentrates its work on areas with active NCCP/HCPs, and high priority areas identified by DFG and other biologists. For example, this map shows which counties received the most attention from CNDDB staff in 2010.