natural bridge

Described by geologists as a “temporary and insecure” landform, an imposing natural bridge is a paradox in stone. Unlike arches, natural bridges always span water or an abandoned waterway and are created by flowing, not seeping, water. The water first breaches a rock wall where it’s been worn wafer thin. Over time, the flow of water widens this portal. Further, finer sculpting and shaping of the opening may be the work of other erosional forces, including sand-laden winds. Natural bridges age and eventually collapse, but in their lifetime they are sometimes strong enough—and flat enough on top—to accommodate vehicular traffic. The grand example of the form is at Rainbow Bridge National Monument in Utah. A sandstone structure 290 feet tall with an opening 275 feet wide, it’s a sacred site for Diné (Navajo) and other Native people. Man-made Lake Powell, when it began to back up behind Glen Canyon Dam in 1964, provided waterborne access to this once remote site. The Diné Nation fought unsuccessfully to prevent oil slicks from motorboats and windblown camping trash from befouling the place, and boat wakes from hastening erosion in the area. Navajo elders say that today this holy site, to which they still journey to evoke rain and to call upon the deep curative powers of the Earth, has lost much of its power. Another well-known natural bridge, a Monacan sacred site located near Richmond, Virginia, was purchased by Thomas Jefferson from George III of England in 1774 for the edification of the curious. It eventually found its way into Melville’s imagination and a description of Moby-Dick: “Soon the fore part of him rose from the water; for an instant his whole marbleized body formed a high arch, like Virginia’s Natural Bridge, and warningly waving his battered flukes in the air, the grand god revealed himself, sounded, and went out of sight.”

Terry Tempest Williams