The west portal opens the Zion-Mount Carmel Tunnel, 1.1 miles or 5,613 feet long, which ASCE calls the longest vehicular tunnel in the National Park system. Bicycles, e-bikes and pedestrians are prohibited and must be carried through by a motor vehicle. It was built with six galleries, and vehicles over 13 feet 1 inch physically do not fit.
The west end of the Zion-Mount Carmel Tunnel sits just above these bends. It runs one mile and a tenth through the cliff, built between nineteen twenty-seven and nineteen thirty. No stopping, no bicycles and no walking. Inside, the windows are the only view. Drivers once pulled off at the big window for a look across Pine Creek Canyon to the East Temple, until a curb put a stop to it. The East Temple is the most visible peak on this whole road. Look down the canyon for the Sentinel, the wall that collapsed and made the valley floor.
Photo: George A. Grant, National Park Service, September 5, 1929, National Archives 520397 · Public domain (U.S. government work)