The key words were "per capita".

The richest county in the US per capita is Teton county Wyoming with an average income of over $250,000.

The confusion may be due to quantity versus quality. Teton county Wyoming has 23,000 citizens, Loudoun county has 440,000, Fairfax county has 1.1 million. Aggregate versus average.

The average income in Teton county Wyoming is over $250,000 a year. I live in Fairfax county I guarantee you I don't make $250,000 a year, nor do a million of its population.

Average per capita income;

• Loudoun county - $62,000 annual

• Fairfax county - $52,000 annual

• Teton county Wyoming - $250,000 annual

From Bloomberg, who also states that Teton county Wyoming is the richest county in the US. https://www.bloomberg.com/news/articles/2019-11-29/richest-u-s-counties-getting-wealthier-from-pitkin-to-teton

The key words were "per capita".

The richest county in the US per capita is Teton county Wyoming with an average income of $340,000.