
Have a look at this map. 
I love maps, and when I was a kid I thought of becoming a cartographer. I can spend hours looking at atlases, Google Earth, etc. In fact I have found Google Earth to be a wonderful companion to reading books about history. You can visualize the terrain the author is describing. 
Anyway, I saw this map linked from an article on Reason Magazine’s website: Washington’s Wealth Boom: The D.C. metro area is getting richer every year. That’s a problem for the rest of America. – Reason Magazine. As you can see they were concerned about the concentration of wealth around the nation’s capital.
You see this map paints the wealthiest counties in the USA red. The statistical anomaly I noted was the areas which we tend to think of as “vacation” spots: The San Juan Islands in Washington, The Lake Tahoe region, the areas around Sun Valley Idaho, Jackson Hole, Wyoming, Park City Utah, the Colorado ski towns of telluride, Aspen, Vail, etc. Outside of LA, SF & Seattle they pretty much make up the “rich” areas of the Western US… exclusively. 
So does this mean the wealthy are not just vacationing there anymore, but have taken up permanent residence? Or was the data collection flawed? Interesting to think about.
(BTW: Can anyone explain the one county in SE Alaska? I thought the rich folks live in Anchorage?)