The Mendocino County Assessor Parcel file consists of Assessor parcel polygons with attribute data derived from the County's property system database. Multiple County Departments contribute data to the property system. The original parcel boundary data was derived from scanned and georeferenced Assessor map pages that were then digitized using "heads-up" digitizing methods, USDA NAIP imagery as well as selected local high resolution black and white aerial imagery were used as control data. Subsequent updates utilize COGO methods when survey data is available. Assessor parcels do not necessarily constitute legal land parcels.