County Map Pro Data & Methodology

County Map Pro is built to make U.S. county geography and public data easier to use. We aim to identify the source and reference period for important datasets so users can understand what each figure represents.

Primary data sources

Our county tools and profiles are designed to rely on authoritative public sources such as the U.S. Census Bureau and other relevant federal, state, and local government datasets.

Geographic boundaries

County and county-equivalent boundaries may change over time. Map boundaries, geographic identifiers, and related data should therefore be interpreted using the source date shown with the relevant tool or dataset.

Data updates

Different datasets are released on different schedules. When a page combines multiple measures, the reference year may differ between measures. We will label important dates and sources where practical rather than implying that every figure was updated at the same time.