"There is." As Pike pulls the olive out of his own and pops it in his mouth. "It's part of the recipe, though no one can really figure out why. Some people prefer no olives, some prefer two,
There is, however, a fascinating little story about a gold miner ordering a drink at the Occidental Hotel in the 1860s, but it's completely made up."

Mostly because the Occidental didn't exist then, they weren't mining gold then, and that drink is also known as the Martinez, which could theoretically have turned into Martini, but it's still nothing more than an urban myth.