Landscape Arch — Thin Stone, Active Collapse
Listen at the stop, then read the transcript and follow the sources behind the story.
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Transcript
Landscape Arch is among the world’s longest natural stone arches and is remarkable for how little rock remains in parts of the span.
In 1991, visitors witnessed slabs of sandstone fall from the underside. The event was not a malfunction. It was the same erosional process that created the arch continuing to operate.
Arches can thin as grains loosen, fractures expand and blocks detach. Eventually every arch will collapse, leaving remnants that erosion continues to reduce.
Ending here makes the park’s central idea unavoidable. The most beautiful forms are not protected from geology by being inside a national park. Conservation can prevent quarrying or vandalism; it cannot—and should not—stop natural collapse. The park protects the process as much as the object.