Dec 6, 2012 ... United States Census Bureau .... extract, map, process, and/or tabulate census
and survey data. .... Block Groups (BGs) are statistical divisions of census tracts,
are ... geographic hierarchy, BGs never cross state, county, or census tract ...
recognized American Indian reservations and can cross state and ...
Block numbering areas (BNAs) are geographic entities similar to census tracts,
and ... American Indian tribal authorities, sometimes with extensive assistance
from the ... the Census Bureau recognized 50,690 census tracts in the United
States ... faced by Dr. Laidlaw, he found that census tracts were a solution. In