The California Delta, where the Sacramento and San Joaquin Rivers meet San Francisco Bay, is one of the most complicated and intensely disputed places in the United States. The region is the largest tidal estuary on the West Coast, and it has subsided to as much as 20 feet below sea level because of agricultural reclamation. The landscape has become a hybrid of natural process and cultural intervention, and its continued existence demands intense management. Protected by a tenuous system of levees, it remains extremely productive farmland, and in the last 50 years, it has gained value in other ways as well: as a site for the explosive growth of Sacramento, Stockton, and the cities of the Bay Area; as a recreational resource; as a commercial shipping route; as the home of threatened and endangered fish species; and as the centerpiece of the system that supplies water to the farms and cities of southern California. All of the forces that shape California converge in the Delta: the changing economics of agriculture; the rapid pace of growth; the prominence of environmental politics; and the apparently endless demand for water.