Via The Decades-Long Comeback of Mark Twain's Favorite Food - When America's favorite storyteller lived in San Francisco, nothing struck his fancy like a heaping plate of this Pacific Northwest delicacy:
... newcomers to the city, including Twain—straight from the Nevada desert with its pickled oysters and an appalling coffee substitute he dubbed “Slumgullion”—developed a taste for the tiny, coppery Olympias. The Oly, as it was called, was the classic gold rush oyster, a staple of celebrations and everyday meals in San Francisco restaurants and oyster saloons. Olys appeared in oyster soup and stew, stuffed into wild poultry and, of course, raw. Perhaps the most distinctive local dish was a “Hangtown fry” of oysters, bacon and eggs.
Mark Twain loved good food. I've had the Olympia oysters, but prefer the Northeast mollusc. I once ate 72 of them in a contest with a friend somewhere where they had an all-you-can-eat raw bar. I lost, but I still love to eat them.
Photo is an Olympia oyster.