Complex sentence: Climbing on named arches within the park had long been banned by park regulations, but following Dean Potter's successful free climb on Delicate Arch in May 2006, the wording of the regulations was deemed unenforceable by the park attorney.
Split into simpler sentences: Climbing on named arches within the park has long been banned by park regulations. Following Dean Potter's successful free climb on the Delicate Arch in May 2006, however, the wording of the regulations was deemed unenforceable by the park attorney.