West Covina, city (1990 pop. 96,086), Los Angeles co., S Calif., in the San Gabriel valley; settled 1905, inc. 1923. Primarily residential, the city has light manufacturing, including power transformers. Before World War II, West Covina was a small rural community where walnuts, wheat, and livestock were raised. Urban and economic growth occurred after 1945, as the Los Angeles metropolitan area began intense development. The city's population increased dramatically in the late 20th cent.