An Unpopulated Heat Map

I've seen a lot of population heat maps of the USA over the years - so it is nice to come across a Bizarro version of a population heat map, a map that actually shows where people don't live.

Nobody Lives Here maps unpopulated census blocks in the USA, the areas where nobody lives. 4,871,270 census blocks, totaling 4.61 million square kilometers, have no-one living inside them. In other words 47 percent of the USA remains unoccupied.

Nobody Lives Here is not a brilliant online map in itself. It uses the Leaflet platform to visualize a non-interactive map created by Nik Freeman. There is nothing wrong with Nik's map. However it would have been nice to see the interactive version of the map overlaid on an OpenStreetMap of the USA, with a transparency control. This would make it easier for us to find out a little more about the actual locations of the unpopulated areas shown on the map.