GPS Location - GNIS vs Census ...
An important aspect of the GNIS code is that it assigns a GPS location (the latitude/longitude) to the geographic feature. This location is simply a point on the map and does not represent the size or shape of the feature. In the case of Walworth, it is a point within Walworth that might be a post office, the city hall or simply an intersection - the point should really be considered arbitrary and only indicating a general location.
For Walworth, the GNIS GPS location is given as:
Lat: 42° 32' 18" (or 42.54°)
Lon: -88° 36' 25" (or -88.61°) [Map]
Determined by its statistical needs, the Census Bureau has defined a sampling area for Walworth - this area also contains a map point. As with the GNIS code, the location of the Census point should be considered as being arbitrary within the sampling area.
For Walworth, the Census 2010 GPS location is given as:
Lat: 42° 34' 4" (or 42.57°)
Lon: -88° 37' 43" (or -88.63°) [Map]
The map point defined by the Census Bureau lies 2 miles to the northwest<1> of the point given by the GNIS (see above).
You might note that the GPS location given for the 2010 Census is different than the location that was specified by the 2000 Census:
Lat: 42° 32' 45" (or 42.55°)
Lon: -88° 35' 45" (or -88.6°) [Map]
The GPS location given for the 2000 Census lies 2 miles to the southeast<2> of the point given by the 2010 Census.