The Inland Empire (IE) is a metropolitan area and region in Southern California, inland of and adjacent to Los Angeles. It includes the cities of western Riverside County and southwestern San Bernardino County, and is sometimes considered to include the desert communities of the Coachella and Victor Valleys, respectively on the other sides of the San Gorgonio Pass and San Bernardino Mountains from the Santa Ana River watershed that forms the bulk of the Inland Empire; a much broader definition includes all of Riverside and San Bernardino counties. The combined land area of the counties of the Inland Empire is larger than ten U.S. states – West Virginia, Maryland, Hawaii, Massachusetts, Vermont, New Hampshire, New Jersey, Connecticut, Delaware and Rhode Island – and is slightly smaller than the combined area of the last five (New Hampshire through Rhode Island).The U.S. Census Bureau-defined Riverside–San Bernardino–Ontario metropolitan area, which comprises Riverside County and San Bernardino County, California, covers more than 27,000 sq mi (70,000 km2) and has a population of approximately 4 million. Most of the area's population is located in southwestern San Bernardino County and northwestern Riverside County. At the end of the nineteenth century, the Inland Empire was a major center of agriculture, including citrus, dairy, and winemaking. Agriculture declined through the twentieth century, however, and since the 1970s a rapidly growing population, fed by families migrating in search of affordable housing, has led to more residential, industrial, and commercial development.