Examination of museum records indicate that 358 species of Trichoptera belonging to 83 genera and 20 families have been collected in California. The families Limnephilidae and Rhyacophilidae exhibited the greatest richness. Museums holding species records from California are listed, which enables localities to be obtained digitally or through museum contacts. Far more digital records for Trichoptera are available from statewide, water-quality monitoring programs than from museums, but identifications are typically made at the generic level where metrics describing pollution tolerance are less valuable than when at the species level. Increased numbers of larval-adult associations may result when researchers can use these museum records to involve volunteer community scientists in making targeted collections to provide specimens for rearing, metamorphotypes, or molecular analysis. This approach could enhance both water quality monitoring and community ecology studies of Trichoptera and other aquatic insects.