The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation.

           Alaska Native Regional Corporations (ANRCs) were created pursuant to the Alaska Native Claims Settlement Act (ANCSA), which is federal legislation
           (Pub. L. 92-203, 85 Stat. 688 (1971); 43 U.S.C. 1602 et seq. (2000)) enacted in 1971, as a 'Regional Corporation' and organized under the laws of the
           State of Alaska as "Regional Corporations" to conduct both the for profit and non profit affairs of Alaska Natives within defined regions of
           Alaska. Twelve ANRCs cover the entire State of Alaska except for the area within the Annette Island Reserve (an American Indian Reservation under the
           governmental authority of the Metlakatla Indian Community). There is a thirteenth ANRC that represents the eligible Alaska Natives living outside of
           Alaska that are not members of any of the twelve ANRCs within the State of Alaska. Because it has no defined geographic extent, this thirteenth ANRC
           does not appear in the TIGER/Line Shapefiles and the Census Bureau does not provide data for it. The Census Bureau offers representatives of the twelve
           ANRCs the opportunity to review and update the ANRC boundaries. ANRCs are represented by a 5 character FIPS code unique within Alaska and a nationally
           unique 8 character National Standard (GNIS) code.