"Grizzly Island Wildlife Area lies in the heart of Suisun Marsh south of Fairfield and Suisun City. The larger Grizzly Island complex, managed by the California Department of Fish and Game, encompasses 15,300 acres, of which 8,600 acres are the wildlife area. The 100,000-acre Suisun Marsh is located where the Sacramento and San Joaquin Rivers blend with the ocean tides. It is the largest estuarine marsh in the continental United States. The area is comprised of tidal flats, salt marshes, managed wetlands, sloughs, seasonal ponds, and upland fields. The wetlands shelter thousands of shorebirds and more than 100,000 wintering waterfowl, including over 230 bird species. The sloughs contain large populations of river otters, while native tule elk are frequently spotted in the upland fields. The recreational opportunities include fishing, hunting, wildlife viewing, bird watching, nature study, and 75 miles of hiking roads and trails."