http://www.census.gov/geo/reference/gtc/gtc_aiannha.html#anvsa 2010 Geographic Terms and Concepts – American Indian, Alaska Native and Hawaiian Native Areas – Geography – U.S. Census Bureau – [retrieved 23Sept2013
Alaska Native village statistical areas (ANVSAs) represent the more densely settled portion of Alaska Native villages (ANVs). The ANVs constitute associations, bands, clans, communities, groups, tribes, or villages recognized pursuant to the Alaska Native Claims Settlement Act of 1971 (Public Law 92-203). Because ANVs do not have boundaries that are easy to locate, the Census Bureau does not delimit ANVs. Instead, the Census Bureau presents statistical data for ANVSAs that represent the settled portion of ANVs. In addition, each ANVSA should include only an area where Alaska Natives, especially members of the defining ANV, represent a substantial proportion of the population during at least one season of the year. ANVSAs are delineated or reviewed by officials of the ANV or, if no ANV official chose to participate in the delineation process, officials of the Alaska Native Regional Corporation (ANRC) in which the ANV is located. An ANVSA may not overlap the boundary of another ANVSA or an American Indian reservation. Each ANVSA is alphabetically assigned a national four-digit census code ranging from 6000 through 7999, an alphabetically assigned state-based five-digit Federal Information Processing Series (FIPS) code, and an eight-digit National Standard (ANSI) code.
Tribal designated statistical areas (TDSAs) are statistical entities identified and delineated for the Census Bureau by federally recognized American Indian tribes that do not currently have a federally recognized land base (reservation or off-reservation trust land). A TDSA generally encompasses a compact and contiguous area that contains a concentration of individuals who identify with a federally recognized American Indian tribe and in which there is structured or organized tribal activity. A TDSA may be located in more than one state (although none do for 2010), but it may not include area within any other American Indian, Alaska Native, or Native Hawaiian area. Each TDSA is alphabetically assigned a four-digit census code ranging from 8000 through 8999, an alphabetically assigned state-based five-digit Federal Information Processing Series (FIPS) code, and an eight-digit National Standard (ANSI) code.