Does Utah have the biggest natural arch in the world? Yes. Sort of. Depends on your definition of “biggest”.
Mapping geologists with the Utah Geological Survey recently published an article in the May 2009 edition of Survey Notes that attempts to answer that question. “In nearly three decades of working in Utah’s geology, I have been asked many times, ‘What is the largest/longest/biggest arch in the world?'” says Grant Willis, article author and UGS mapping geologist. “For years I told people it was Landscape Arch in Arches National Park.”