Modesto (mōdĕsˈtō) [key], city (1990 pop. 164,278), seat of Stanislaus co., central Calif., on the Tuolumne River, near the northern end of the San Joaquin valley; inc. 1884. The center of a farming and fruit-growing area, it has food-processing and canning plants, wineries, fruit orchards, and diversified manufacturing. Modesto also ships meat and dairy products and produces nuts, vegetables, and rice. It was one of the fastest-growing U.S. cities in the late 20th cent.