About CountyAtlas

Who runs CountyAtlas

CountyAtlas is built and maintained by Marko Visic, BSc Physics, University of Ljubljana (Faculty of Mathematics and Physics, University of Ljubljana). A physics training is a training in working carefully with primary data — measuring, quantifying uncertainty, and refusing to report a number the evidence doesn’t support. That is exactly the discipline CountyAtlas applies to public U.S. data: every figure traced to an official source, its vintage recorded, and anything unreliable left out rather than guessed.

CountyAtlas is operated by Moving Data Systems d.o.o., an independent company based in Slovenia. It has no sponsors, clients, or paid data partners that could influence what the numbers say — it is simply a reference built to be correct and citable.

What CountyAtlas is

A reference site for U.S. county geography and statistics. For each state it publishes an interactive, colour-by-any-measure county map, a sortable data table of every county, print-ready map downloads, and clear answers to the questions people actually search — how many counties a state has, which is the richest or most populous, and where a given city or address falls. The location tools answer “what county / city / state / congressional district am I in?” from a point on the map or a typed place.

Why you can trust the data

Every number on CountyAtlas comes from an official primary source, and each carries the vintage it reflects:

• Boundaries and geography — the U.S. Census Bureau’s TIGER/Line (TIGERweb).
• Population — the Census Population Estimates Program (PEP).
• Income and poverty — the Census Small Area Income & Poverty Estimates (SAIPE).
• Age and educational attainment — the Census American Community Survey (ACS), 5-year.
• Unemployment — the Bureau of Labor Statistics’ Local Area Unemployment Statistics (LAUS).
• ZIP-code areas — the HUD–USPS ZIP Code Crosswalk (public domain), for ZIP-to-county lookups.
• County seats — Wikidata (CC0), each validated against a Census place inside its county.

The governing rule is verified or omitted: a value is shown only when a source confirms it, and unreliable estimates (a coefficient of variation ≥ 0.30) are left blank rather than published as a wrong number. The full sourcing, vintages, and methodology — including how CountyAtlas handles the disputed U.S. county count and Connecticut’s planning regions — are documented on the methodology page, the site’s authoritative data-standards reference. The complete dataset is available as a free, openly-licensed CSV.

Independence & funding

CountyAtlas is free to use. It does not currently run advertising and has no paid sponsors or data partners — nothing that could shape which figures are shown or how they’re presented; the data comes entirely from the official sources above. If advertising is introduced later it will be disclosed in the privacy policy, and it will not change how the data is sourced or reported.

Contact & corrections

Found a figure that looks wrong, or have a question? Corrections are genuinely welcome — reach us at info@countyatlas.org or via the contact page.