Has the recession actually made us all richer?

You might be surprised to learn where the richest people live. Is it New York? Is it San Francisco?
Moving choropleth chart that shows the 1998 - 2013 median income in the U.S. by county.
This graph above is intended to show changes over time in the relative income of each household in the U.S. by county. Don't spend too much time focusing upon county by county comparisons. Instead look for overall trends. Dark red represents the richest while dark blue represents the poorest counties. Over time notice how the red tends to spread out. This means wealth is actually spreading out over time. The wealth of the poorest counties expressed as a percentage of the wealthiest counties is increasing.

So are the rich people moving to increasingly rural areas? Or, are rural areas increasing in wealth over time? If this were a graph of the average income, it could be that the richest are moving into more rural areas. However, since this graph shows the median income this suggests that the each these areas are actually increasing in wealth. Another explanation might be that these counties are actively seeking to increase the attractiveness to new business developments. This could mean these counties are undergoing a sort of gentrification. As new businesses are built, the cost of living tends to slightly increase and this sort of positive cycle of growth occurs.

What really helps support this theory is the case study taking place in Minot, ND. Take a look at the static image below. Notice the dark blotch in the middle of North Dakota (top middle of the map). In 2000 this was an extremely poor area. Now in 2012 this county is actually one of the richest in the entire U.S.! What happened? I had to check for myself. It turns out that they struck gold- black gold. The oil boom is a perfect example of how the wealth in counties such as Minot is increasing due to industry. It seems as though the 2007 recession helped to spread some of the wealth from the Eastern corridor throughout the rest of the country. What are your thoughts?
2013 relative U.S. median housing cost by county.
Data Source: www.census.gov/