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Understand Idaho

2021 redistricting plans

The Idaho Commission for Reapportionment's two plans adopted November 10, 2021 after the 2020 census: Plan L03 (35 legislative districts) and Plan C03 (2 congressional districts). Both took effect for the 2022 election and remain in force until the next reapportionment.

Publisher

Organization
Idaho Legislature
Publisher’s dataset
Reapportionment plans L03 and C03, 2021
File or API used
https://legislature.idaho.gov/wp-content/uploads/redistricting/2021/Final_Report/L03_BlockEquivalency.pdf
Retrieval script
scripts/fetch-idaho-redistricting-2021.py
Methodology
https://legislature.idaho.gov/wp-content/uploads/redistricting/2021/Final_Report/Final%20Report.pdf

Coverage

Geography
Idaho's 44 counties
Time coverage
2022-2031 (districts in force until the next reapportionment)
Update frequency
Decennial, after each census
Published
November 10, 2021
Retrieved
September 10, 2026
License of the records
Idaho public record.
Rows
114 records

Measures

MeasureWhat it measuresUnit

Records

One row per (plan, county, district): which Idaho legislative districts (Plan L03) and congressional districts (Plan C03) cover each county.

  • plan: "L03" (35 legislative districts) or "C03" (2 congressional districts).
  • geo: The county's 5-digit FIPS code, matched from the census block GEOID's first five digits.
  • county: County name, without the word "County".
  • district: District number, as an integer.
  • whole: True when the entire county is in this one district; false when the county is split and this is one of the districts it touches.

Caveats

  • The Idaho House assigns two seats (A and B) per legislative district and the Senate one; this table gives the district only, not the seat.
  • A county split between districts is listed once per district it touches, from the census-block equivalency table (each 2020 census block carries exactly one district); it is not weighted by population.
  • Plan C03's block equivalency table and Plan L03's cover the same 81,879 Idaho census blocks; district assignment is independent between the two plans.
  • Cross-checked against the Commission's own Political Subdivision Splits Report (Final Report Appendix VIII for L03, Appendix IX for C03): the split counties and districts agree exactly.

How to cite

Understand Idaho, “Reapportionment plans L03 and C03, 2021”, compiled from Idaho Legislature, Reapportionment plans L03 and C03, 2021. Retrieved September 10, 2026. https://understandidaho.com/data/idaho-redistricting-2021/.

Cite Idaho Legislature directly for the figures themselves.

This page was last updated .