places, as well as information on boundary changes. The Census Bureau then provides all the BAS information to a representative of the State government—the State certifying official—for confirmation and certification.
The Census Bureau’s computerized geographic data base of the entire Nation, the TIGER data base, stores information about features (such as roads, rivers, lakes, railroads, and power lines) and boundaries, along with information about the relationships among them. Since 1988, the Census Bureau has produced, from its TIGER data base, digital maps for the BAS. All information obtained through the BAS is then entered into the TIGER data base so that all subsequent TIGER System products reflect these changes.
Census designated places (CDPs) are communities that lack separate governments but otherwise resemble incorporated places. They are settled population centers with a definite residential core, a relatively high population density, and a degree of local identity. Often a CDP includes commercial, industrial, or other urban types of land use. Before each decennial census, CDPs are delineated by State and local agencies, and by tribal officials according to Census Bureau criteria. The resulting CDP delineations are then reviewed and approved by the Census Bureau. The Census Bureau has used slightly different definitional criteria for CDPs, depending on their geographic location; such specialized criteria reflect the uniquely different living conditions or settlement patterns found in certain areas and the relative importance of settlement size. Examples are the CDPs inside UAs and outside of UAs, and the CDPs in Alaska, Hawaii, Puerto Rico, the Outlying Areas, and on American Indian reservations (for details, see the section in this chapter entitled “Criteria for Delineation of CDPs in the 1990 Census”). Although only about one-fifth as numerous as incorporated places, CDPs are important geographic units; they permit the tabulation of population counts for many localities that otherwise would have no identity within the Census Bureau’s framework of geographic areas. In 1990, over 29 million people in the United States resided in CDPs (see Table 9-4).
