The Museum's collections cover the geographic area generally defined by those areas of northern Sonoma County that currently utilize, or in the past utilized, the City of Healdsburg for education, trade, commerce or governmental or professional services. This larger Healdsburg community is loosely defined by the following inclusive boundaries: North - the Sonoma/Mendocino County line; South - the town of Windsor (inclusive of); East - the county line at Knights' Valley; West - Hacienda Bridge at the Russian River.

Gathered and preserved by the community since 1952, the Healdsburg Museum holdings comprise one of the finest regional collections in the state.