Land Mass and Population

Half of the total US population is clustered in less than 5% of its counties — that is just 146 out of over 3000. Eyeballing it, it looks like about ~7% of the continental land mass (not counting Alaska, which is huge).

Imagine that: Much less than 10% of the land mass houses more than half the population.

 http://www.ritholtz.com/blog/2013/09/half-of-us-populaton-lives-in-10-of-the-land-mass/