Leonard P. Zakim (Bunker Hill) Bridge, Boston-Cambridge, Massachusetts (Charles River)
Sunshine Skyway, Saint Petersburg-Terra Ceia, Florida (Tampa Bay)
Golden Gate Bridge, San Francisco-Marin County, California (San Francisco Bay)
Brooklyn Bridge, New York City (East River)
Royal Gorge Bridge, Cañon City, Colorado (Arkansas River)
Dr. Joan Bushwell's Chimpanzee Refuge 
How did the Mackinac Bridge, joining Michigan’s upper and lower peninsulas not make this list? It’s still, 53 years after its construction, the longest suspension bridge in the western hemisphere.