Like so many other things at Zion, it’s difficult to do justice to the scale of things with a photograph. The Great Arch is 580 feet high, 720 feet long, and 90 feet deep, according to Moon’s Zion and Bryce handbook. It’s a shame it’s not like the old days, when you could get out of your Model T in the Zion-Mt. Carmel Tunnel and peek through the portals they built. Even the glimpses of The Great Arch as we passed by the portals at 30 mph were astonishing.