You realize why that is, I hope.
Most people, rationally, travel from city to city along the interstate highways.
For equally logical reasons businesses tend to cluster along those highways, while towns and roads away from them tend to stagnate or fall back in population.
Even in our most populous states, such as CA or FL, there are still large areas that are almost deserted. For instance, take the Florida Turnpike north from the coast to Orlando. Almost nothing along the entire 100+ miles but cows.
Similarly I-5 in CA from Stockton to Bakersfield, not even in the real desert, is very much like driving across Wyoming.
If you fly from coast to coast, long stretches across the western US there is nothing to see below except an occasional road. No houses, no towns.
IOW, you choose to live and drive where everybody else chooses to live and drive, then complain that it's too crowded. I agree with you, BTW, but I at least recognize that it's my choice to go where all the people are. You or I have the choice to go where there are very few other people.
Freepmail me and I'll be glad to send you some suggestions.
You are talking to one of the best travelled in America people that you could know, I have been travelling this country in every mode of transportation for 55 years, I have lived in many, many states, I was what used to be called a drifter for much of my life, I even lived for years as the classic drifter as a hitchhiking traveler with no destination, living on odd jobs and such, all the time seeing the nation from close up, back roads, Interstates, and everything in between. The majority of my life has been spent in the west and southwest, I am well aware that from a plane, there is vast amounts of empty space.
The reason America appears overcrowded to me is that it is, more than doubling our population in my life time has been a setback for the quality of life here.
When I was a youth and our schools taught American, they taught us about the over populated hell holes of the world, like India and China, (The United States was a distant third in population at the time) now we are approaching what those nations populations were at that time.
Personally I liked America better a 100 or even a 150 million people ago.