Marjorie Harris Carr Cross Florida Greenway, The Island.Marjorie Harris Carr Cross Florida Greenway, The Island. This most fascinating remnant from the largest failed public works project in the history of the country, the Cross-Florida Barge Canal, includes four massive stanchions erected in the 30’s that were meant to hold a roadway that would pass over what was to be a section of the barge canal which was never dredged.