Blackwater River State Park is considered one of the purest sandbottom rivers in the world, the Blackwater River is in its natural state for almost its entire length. Beginning 45 miles upstream in Alabama, it continues downstream for 13 miles before emptying into Blackwater Bay. The river's sand bottom, dark tannin waters and contrasting large, white sandbars have drawn worldwide attention and provide the perfect setting for this 590- acre park.