National 2020 AIANHH (American Indian Area / Alaska Native Area / Hawaiian Home Land) Block Assignment File and Tribal Block Group Indicator for 2020 Blocks

## RDH Retrieval Date
01/17/2023

## Sources
Block PL 94-171 2020 for all 50 states from [RDH](redistrictingdatahub.org)
AIANHH shapefiles for all states where relevant from [RDH](redistrictingdatahub.org)
County shapefiles for all 50 states from [RDH](redistricingdatahub.org)

All data was originally sourced from the U.S. Census Bureau.

## Fields
GEOID20		Unique Block ID from the Census
STATE		State Name
STATEFP20		State FIPS
COUNTY		County Name
COUNTYFP20	County FIPS
TRACTCE20		Tract Cell Enumeration
BLOCKCE20		Block Cell Enumeration
IN_AIANHH		Indicator for if the block is in a AIANHH (YES/NO)
IN_TBLKGRP	Indicator for if the block is in a Tribal Block Group (YES/NO)
AIANHH_NAME	AIANHH Name where applicable
AIANHH_GEOID	AIANHH GEOID (concat of AIANHH field and AIHHTLI field)
AIANHHNS		FIPS American Indian Area/Alaska Native Area/Hawaiian Home Land Class Code
AIHHTLI		American Indian Trust Land/Hawaiian Home Land Indicator
AIANHH		American Indian Area/Alaska Native Area/Hawaiian Home Land (Census)
AIANHHFP		American Indian Area/Alaska Native Area/Hawaiian Home Land (FIPS)
AIANHHCC		FIPS American Indian Area/Alaska Native Area/Hawaiian Home Land Class Code
TTRACT		Tribal Census Tract
TBLKGRP		Tribal Block Group
AITS			American Indian Tribal Subdivision (Census)
AITSFP		American Indian Tribal Subdivision (FIPS)
AITSCC		FIPS American Indian Tribal Subdivision Class Code
AITSNS		American Indian Tribal Subdivision (NS)

## Processing Steps

Block PL data was downloaded by state and queried to fields of interest (see above).
If a block had a value other than '9' for the TBLKGRP field, it was given a IN_TBLKGRP indicator of 'YES' while blocks with '9' were given 'NO' as '9' is the Census' null value for this field.
The AIANHH_GEOID was created by combining the AIANHH and AIAHHTLI fields. This provides a unique GEOID for each type of AIANHH classification. The AIANHH_NAME field was populated using the AIANHH_GEOID field by retrieving the corresponding data in the NAMELSAD20 field of the AIANHH shapefile (the AIANHH_GEOID field is titled GEOID20 in the AIANHH shapefile).
If a block had a value other than '9999' for the AIANHH field, it was given a IN_AIANHH indicator of 'YES' while blocks with '9999' were given 'NO' as '9999' is the Census' null value for this field.
County names were added to the file by using the COUNTYFP20 field to retrieve a corresponding name from the county shapefile.
All row where a '9','99','999','9999','99999', or '999999' string was used to signify no data from the Census, were modified to a value of "NULL".

This processing was run for each state and then combined into one file to create a national file.
All 8,126,956 blocks in the 50 states are included in this file (DC and territories are not included).
All areas where a block is noted as YES for IN_TBLKGRP are also YES for IN_AIANHH, but not all blocks with IN_AIANHH as YES have a value of YES for IN_TBLKGRP (not all are located in Tribal Block Groups).

## Additional Information
You can view the code to create this file on our [GitHub](https://github.com/nonpartisan-redistricting-datahub/Processing-Requests/National_AIANHH_BAF_01_10_2023/)

For more information on this file, please contact info@redistrictingdatahub.org