Puget Sound Regional CouncilBlock groups are clusters of blocks within the same census tract that have the same first digit of their 4-character census block number from the same decennial census. Block groups delineated for the 2000 Census generally contain between 600 and 3,000 peoplee, with an optimum size of 1,500 people. Local participants delineated most block groups as part of the Census Bureau`s Participant Statistical Areas Program (PSAP). The Census Bureau delineated block groups only where a local or tribal government declined to participate or where the Census Bureau could not identify a potential local participant. A block group usually covers a contiguous area. Each census tract contains at least one block group and block groups are uniquely numbered within census tract. Within the standard census geographic hierarchy, block groups never cross county or census tract boundaries, but may cross the boundaries of county subdivisions, places, urban areas, voting districts, congressional districts, and American Indian, Alaska Native, and Native Hawaiian areas. Technical Documentation: https://www2.census.gov/geo/pdfs/maps-data/data/tiger/tiger2k/tiger2k.pdfArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/17ce28588b694f4189be137d2d8e715b_0engPuget Sound Regional Council Data PortalPublicCensus Block Groups 2000 [Washington (State)--Puget Sound Region]Web servicesWashington (State)--Puget Sound RegionWashington (State)2000