Below are the US counties with the highest per-capita income (as of 2018), according to this recent Bloomberg article:

Teton, WY is home to the Jackson Hole valley (which has some of the best skiing in the world). And Pitkin, CO is home to Aspen. Turns out, rich people like ski towns.

Interestingly enough, 2018 saw per capita income grow in the greatest number of US counties since 1981. According to the Bureau of Economic Analysis, it was 97% of all counties:

For the full Bloomberg article, click here.

Charts: Bloomberg