June 25, 2022

Proposal for Census Block Group Change

The Fall River County GIS Department is proposing a change to the census block groups for the 2020 census.  Individuals or organizations that use the census block group demographic information are encouraged to read the proposal and provide feedback.  Comments, suggestions, and other feedback should be directed to Stacey Martin at 605-745-7584 or [email protected] by April 30th.


What is a Census block group?

A block group is the smallest census division for which the public can obtain demographic information (median age, income, etc).  This information is often used by groups applying for grants.


Problems and Solutions

Ideally block groups should contain populations that are similar in their demographics.  If for instance a block group contains both a low-income area and a subdivision of millionaires, the median income information is going to fall between the two groups but does not actually represent either population.

For grant writing it is also helpful for block groups to represent populations that receive services from the same community.   A block group that contains populations that receive services from Edgemont and Hot Springs is less useful for those writing a grant for one community or the other.

The attached maps show the issues with the existing block groups and a proposal to be submitted to the US Census Board for changes to those groups.


There are limitations on how we can divide the block groups.  There are minimum and maximum population thresholds that must be met.  The census also has specific features that can or cannot be used as dividing lines.  This is the reason that boundaries are often a squiggly line following a creek or road instead of a nice straight line following a school district boundary.



Anyone with feedback regarding these proposed changes should contact Stacey Martin at 605-745-7584 or [email protected] before April 30th.  Feedback, issues, or concerns will be considered for the final proposal to be presented to our local governing councils (county commissioners, city councils, etc) at their first meetings in May.



The US Census Bureau generally does not like changes to boundaries that are as extreme as what we are asking for in this proposal.  This proposal would have a greater chance of acceptance if accompanied by letters of support from our local governing councils and service organizations.

Download: census proposal


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