When Jim Knudson bit into his first taco during dinner at a friend's house in 1949, he knew he had tasted something special. He added the item—which many diners were pronouncing "tay-co"—to the menu at his restaurant in Grass Valley, California. Determined to introduce the food to as many people as possible, Jim and his wife, Margaret, converted a 16-foot trailer into a kitchen on wheels. They adopted the nickname Jim had earned from one of his longtime customers and drove up to Lake Tahoe, where Jimboy's Tacos found its first permanent home.

Locals, tourists, and even members of the Rat Pack flocked to the tiny taco stand for the uniquely seasoned, parmesan-dusted ground-beef taco, the anchor of a growing menu. The family eventually relocated to Roseville, California, where they set up a small taco stand and began branching out to other locations in and around Sacramento.

Today, Jim Knudson’s daughter Karen, the current president of the company, carries on the legacy of taco obsession at more than 40 locations in northern California and Nevada. Guests who arrive early for breakfast might glimpse the cooks slowly simmering beans, mashing avocados into guacamole, and preparing their signature ground beef with trans-fat-free oil. In addition to classic corn-tortilla tacos, the menu holds the mega-size flour-tortilla El Gordo, golden-fried taquitos, and even a taco burger that fuses Mexican and American culinary traditions.