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 to conduct both the for-profit and non-profit affairs of Alaska Natives within a defined region of Alaska. For the Census Bureau, ANRCs are considered legal geographic entities. Twelve ANRCs cover the entire state of Alaska except for the area within the Annette Island Reserve (a federally recognized American Indian reservation under the governmental authority of the Metlakatla Indian Community). A thirteenth ANRC represents Alaska Natives who do not live in Alaska and do not identify with any of the twelve corporations. The Census Bureau does not provide data for this thirteenth ANRC because it has no defined geographic extent and thus it does not appear in the TIGER/Line Files. The Census Bureau offers representatives of the twelve non-profit ANRCs in Alaska the opportunity to review and update the ANRC boundaries before each decennial census.

The ANRC boundaries are those reported as of January 1, 2021.