Diablo

"arguably the highest of the high-end East Bay enclaves"

Just after the turn of the century, R.N. Burgess turned a cattle ranch into a posh new East Bay resort. Then he built his dream house. What possessed him? Clearly, Diablo made him do it, SF Gate (2002)
https://www.sfgate.com/bayarea/article/Just-after-the-turn-of-the-century-R-N-Burgess-2847539.php#taboola-2

The Burgess Era: Building a Community with an Ideal, Diablo Country Club Newsletter (2023)
https://issuu.com/diablocc/docs/diablocc_winter_2023_newsletter/s/19272530

One of the oldest communities in the Bay Area at the foot of Mt. Diablo, Diablo has some of the oldest homes and buildings in the Bay Area. Comprised of both old money and "new old money" (some of it from the Gold Rush era, no doubt) the earliest structures date back to the 1870s.

In the early 1900s, tycoon Robert Noble Burgess (a partner of William Randolph Hearst) built a resort and vacation homes where San Francisco's elite could escape from the summer fog.

A golf course was designed by Jack Neville, the golfer and course architect who designed the world-famous Pebble Beach Golf Course near Carmel and the famous "17 mile drive" in northern California.

Herbert Hoover once gave a speech at the Clubhouse.