Locus Franklin County Census geography audit. Python 3 standard library only. Run python county_audit.py from the extracted folder. Inputs: US Census Bureau 2024 ACS five-year B19013 and 2020 ZCTA-to-tract relationships. Sources: https://www2.census.gov/geo/docs/maps-data/data/rel2020/zcta520/tab20_zcta520_tract20_natl.txt and https://www2.census.gov/programs-surveys/acs/summary_file/2024/table-based-SF/data/5YRData/acsdt5y2024-b19013.dat . County extension is exploratory; weighting check was added after initial county results. Association uses largest land overlap, not population allocation. Intervals use published MOEs; separation is not a joint significance test. Pairs are dependent. Percentages do not estimate business success, spending, demand or wrong-site probability. Census does not endorse Locus. Findings calculated 31 October 2026. Source files unchanged; SHA256.json records exact input bytes.