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 a 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 …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 a 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.