Natural Bridge is a geological formation in Rockbridge County, Virginia, comprising a 215ft natural arch with a span of. It is situated within a gorge carved from the surrounding mountainous limestone terrain by Cedar Creek, a small tributary of the James River. Consisting of horizontal limestone strata, Natural Bridge is the remains of the roof of a cave or tunnel through which the Cedar Creek once flowed.Natural Bridge has been designated a Virginia Historic Landmark and a National Historic Landmark. Since 2016, the bridge and its surroundings have been managed by the Commonwealth of Virginia as Natural Bridge State Park.GeologyRocks in the area are limestones and dolomites from the Ordovician Period, which implies deposition about 470 million years ago. The carbonates of the Natural Bridge occur within the Chepultepec Formation, making the buttress of the bridge, and the Beekmantown Formation, deposited conformably over the Chepultepec and comprising the span and the upper part of the bridge. Strata at Natural Bridge are close to horizontal, in contrast with dipping and folded beds as close as away along Highway 11, which points to the fact that structurally the rocks making the Natural Bridge are the bottom part of a syncline.
