Wary of releasing any data that might reveal something about individual taxpayers, the IRS slices its statistics into broad ranges. In this data set the top tier of income is $200,000 and up. Except, perhaps, to a politician looking for revenue increases, this scarcely qualifies a taxpayer as wealthy.
So I put a finer sieve on the database, zeroing in on communities where the average income within the 200K-and-up set is at least $1 million.
Result: a set of 130,400 tax returns from 64 hot spots of prosperity–suburbs, islands, parts of cities.
The resulting article is called America's Millionaire Capitals, which, boiled down, results in two top-20 lists, one of cities with the highest average net worth (among filers with at least $200,000 in average gross income), the other of cities with the highest average gross incomes (among returns of $200,000 and over).
So do any Bay Area enclaves make an appearance? Yes they do. On the net worth list, Atherton, in San Mateo County, logs in at No. 6. In the highest-incomes set, Atherton comes in No. 5, and Ross, in Marin County, No. 20.
Figuring I'd be stopped at the town gates and imprisoned, I've never been to either of these two places. Perhaps you haven't either. But you can find some nice area photos below, including some "Lifestyles of the Rich and Famous" shots, on Flickr. (Two more here and here.)