Harbor Island is a small residential island located 14 miles (22 km) east of Beaufort, South Carolina. It is one of the Carolina Sea Islands. The swing drawbridge has been replaced by a fixed high level bridge., Harbor River Bridge, that connects the island to Saint Helena Island towards the west. A small causeway crossing Johnson Creek connects Harbor Island with Hunting Island towards the south. The majority of the island is tidal marsh, though approximately 800 acres (3.2 km2) of upland acreage exist on the northeastern portions of the island.