Located in northern California, the Suisun Marsh ( ) has been referred to as the largest brackish water marsh on west coast of the United States of America. The marsh land is part of the San Francisco Bay tidal estuary, and subject to tidal ebb and flood. The marsh is home to many species of birds and other wildlife, and is formed by the confluence of the Sacramento and San Joaquin rivers between Martinez and Suisun City, California and several other smaller, local watersheds. Adjacent to Suisun Bay, the marsh is immediately west of the legally defined Sacramento-San Joaquin Delta as well as part of the San Francisco Bay estuary. The Suisun Marsh is named for the Suisunes, a Patwin/Wintun sub-tribe, who inhabited the area around 200 years ago. Overview Suisun Marsh, 116,000 acres (470 km2) of land, bays, and sloughs, is one of the largest estuarine marshes in the western United States. Geologically, the Suisun Marsh is the product of water-borne sediment deposition, carried from the Sacramento and San Joaquin Rivers into the San Francisco Bay. This process—the weathering of the parent rock of the Sierra Nevada and Vaca Mountains, transport of the weathered material via rivers and creeks, and ultimate deposition into San Francisco Bay—has taken place over thousands of years and has resulted in the patchwork nature of the marsh. The marsh areas consist of peat soils formed by the decay of emergent plants over time. Originally, Suisun Marsh was a vast stretch of tidal wetlands broken by branching tidal channels and ponds. The area alternately flooded and drained with the rise and fall of the tides. In winter, the ponds supported high numbers of migratory waterfowl. From the years of the Gold Rush to about 1880, the marsh was extensively used by market hunters to provide fresh waterfowl and feathers to San Francisco markets. From the 1880s until the 1930s, however, this area was gradually converted to agriculture, made possible by the construction of levees and dikes to hold back the water. Eventually, increasing soil salinity made cultivation and even cattle grazing unprofitable and cultivation ceased on all wetland areas. Most of the marsh was then purchased by public and private interests as habitat for waterfowl, mainly to support hunting. Later, the construction of water development projects (specifically, the federal Central Valley Project and the California State Water Project) in the Sacramento-San Joaquin watersheds altered the