Guana River State Park is a state park, located on San Pablo Island, a barrier island on Florida's First Coast. It has recently been designated as the Guana Tolomato Matanzas National Estuarine Research Reserve and is the 25th National Estuarine Research Reserve in the United States. The park is located on portions of San Pablo Island along State Highway A1A, between St. Augustine and Jacksonville. Located both in St. Johns and Flagler Counties, the park is a federal/state partnership with the Florida Department of Environmental Protection as the state program administrator.
Within its 60,000 acres (240 km²) are beaches, sand dunes, salt marshes, mangroves, tidal wetlands, tidal creeks, oyster bars, estuarine lagoons, maritime hardwood hammock, freshwater depression marshes, pond pine flatwoods and shell mound forests.
Activities include hiking, fishing, boating, picnicing, and wildlife viewing.
Amenities include over nine miles (14 km) of nature trails and an unspoiled natural setting. The reserve also contains seventeen archaeological sites, shell middens at Shell Bluff Landing and Wright's Landing, as well as a prehistoric earthen burial mound. Guana continues to be a community gathering for fishing, canoeing, and other aquatic activities.Fishing is excellent at times for redfish, seatrout, croaker, black drum and spot. You can fish at the dam and along the banks of the impoundment and the ponds. The impoundment is also a popular spot for crabbing. Boat ramps are located at Guana Lake Dam and off A1A at Six Mile Landing.