Where can I get (USA) county neighbour relationship data?
I need a graph where each node is a US county and each edge represents a border shared between counties. I do not particularly care about the absolute position or shape of each county (though that would be a plus).
Where can I find that information (for free)? Army Corp of Engineers? US Geo Survey?
Ideally, I could just get a csv list something like
- FL-Polk, FL-Lake
- FL-Polk, FL-Orange
- FL-Polk, FL-Osceola
- etc for every county, including "kitty-corner" borders, borders across water, or across state borders
I'm a programmer so expect I can handle any standard exchange format. (That could just be hubris though). (I don't have any cool GIS apps. Just humble scripting in perl and python.)
Your best lookup table would be the U.S. Census Bureaus State and County FIPS codes. Alpha tables invariably have different standards for naming and formatting. I've found that the FIPS codes are the best.
