These are the same maps as are on the main Maps-I-Like page. This page also includes the source links and info.
See also
– Misc-Maps-I-Like sources
– Geo-Data-Viz-I-Like sources
Mono-Thematic maps are ones in which there is only one data layer shown on the map (and nothing else, not even land, water or text).

Optimal routes from the geographic center of the contiguous U.S. to every county.
(Topi Tjukanov)
https://tjukanov.org/roadsofamerica/

Rivers of USA (Robert Szucs)
https://www.etsy.com/listing/486172257/river-basins-of-the-us-in-rainbow

The “McFurthest Spot” (distance to a McDonalds)
Stephen Von Worley
http://www.datapointed.net/2010/09/distance-to-nearest-mcdonalds-sept-2010/
Mono-Thematic maps have only one data layer shown on the map (and nothing else, not even land, water or text). Not to be confused with monochromatic maps…