California Citrus State Historic Park preserves one of the last remaining citrus groves in the Inland Empire, once known as the Orange Empire. The citrus industry of California was known as the 'second gold rush'. In the 1870's, the introduction of the navel orange created an extreme economic boom. The parallel boom of the railroad industry allowed the 'gold' to be shipped across the country and America went crazy. Though the boom today is only a fragment of its past, it is still a billion dollar industry in California. Park trails allow visitors a glimpse into the romanticized orange groves that made California famous.