Sea Rim State Park, 4,141.1 acres of marshland with 5.2 miles of Gulf of Mexico beach shoreline, is located in Jefferson County, south of Port Arthur.
Acquired by purchase from Planet Oil and Mineral Corporation and Horizon Sales Corporation in 1972, Sea Rim State Park opened to the public in 1977. "Sea rim" refers to the portion of the Gulf shoreline where marsh grasses meet the surf. These marshlands formed when silt from the Sabine River delta was carried down the beach by longshore currents. A unique environment, Sea Rim provides a valuable habitat for many wetland species.