St. Marks River State Park is a Florida state park about 10 miles east of Tallahassee, south of U.S. Highway 27, spanning 2,589 acres in parts of Jefferson and Leon counties. Opened in 2007 as Florida’s 161st state park, it was created to help protect the St. Marks River. Its land serves as a buffer against surrounding development, preserving a stretch of river landscape near the state capital. The park’s importance rests chiefly in that conservation role, safeguarding the character of the river corridor in a growing region.