of dams and canals. The even larger California State Water Project was formed in the 1950s, consisting of the California Aqueduct and its ancillary dams. The California Aqueduct, developed at the cost of several billion dollars, helps store and transport water from the Feather River Basin to agricultural and municipal users statewide. The Colorado River Aqueduct delivers water from the Colorado River to the Imperial Valley of California area and since 1905 the Los Angeles Aqueduct delivers water over from the Owens Valley to the city of Los Angeles. One of the state's most acute problems is its appetite for water. In the extensive fields of the Imperial Valley, irrigation is facilitated in part by the All-American Canal—part of the Colorado River Aqueduct project. Cutbacks in federally funded water projects in the 1970s and 80s led many cities to begin buying water from areas with a surplus; but political problems associated with water distribution continue. Ongoing challenges to develop a long-term plan to end surplus water withdrawals from the Colorado led the federal government to stop the release of surplus river water to the state in 2003. Agriculture is one of the prominent elements of the state's economy: California leads the nation in the production of fruits, vegetables, wines and nuts. The state's most valuable crops are cannabis, nuts, grapes, cotton, flowers, and oranges. California produces the major share of U.S. domestic wine. Dairy products contribute the single largest share of farm income. California's farms are highly productive as a result of good soil, a long growing season, the use of modern agricultural methods and extensive irrigation. Irrigation is critical since the long dry summers would not allow most crops to grow here--California Indians had almost no agriculture because of this. Extensive and expensive irrigation systems including furrow "gravity" irrigation, sprinkler and drip irrigation systems have been developed to supply the extensive irrigation needs of California. Illegal immigration to the United States has been traditionally drawn to the state, in part, because corporations face intense pressure to control labor costs by using illegal means to harvest California's extensive crops. California's location along the Pacific coast and its rapidly growing population initially led to the constructions of major seaports at San Francisco in the San Francisco Bay area and inland ports at Sacramento, etc. The first paddle steamer, the , arrived in the port of San Francisco on February 29, 1849,