I want to create map tiles for all of the United States at high zoom level (12 or 13). I am using TileMill and mapping census tracts (income).
However, I only need the high zoom level for populated areas. How could I exclude the areas with low population?
I want to do this to minimize tile generation time and webhost disk space.
For instance, I'm going to treat Alaska separately as most of it has low population density. I can also exclude oceans and large lakes. I could probably exclude a large portion of WY, ND, SD, and several other western states.