When people stand at the rim of the amphitheater in Utah’s Cedar Breaks National Monument and look down on an otherworldly landscape of multicolored rock spires, pinnacles, and other geologic oddities, they’re looking across tens of millions of years of Earth’s history. The same can be said when viewing the bowl-shaped escarpment from space.
The OLI-2 (Operational Land Imager-2) on Landsat 9 captured this view of the amphitheater’s semicircular rim and deeply eroded drainages on June 18, 2025. The erosive power of water from Ashdown Creek and several tributaries, along with relentless physical and chemical weathering, is evident in the many channels, cliffs, and canyons that radiate outward from the rim and define the escarpment and amphitheater.
The feature’s striking rock formations are composed of sedimentary rock layers laid down roughly 50 to 25 million years ago within a basin that, at times, held a large body of water called Lake Claron. Many of the amphitheater’s limestone layers began as sediments that settled on its lakebed as carbonate-rich muds.
Differences in rock type and color, evident in the layering seen in ground photographs and to a degree in Landsat images, reflect differences in environmental conditions during deposition. Lake Claron, for instance, was sometimes quite deep, but during dry periods it was shallow or nonexistent. In wet conditions, iron in muddy sediments was scarce or had too little exposure to oxygen to oxidize, or rust, leaving the resulting rock white or gray. During drier periods, iron in sediments had greater exposure to oxygen, forming minerals that turned layers red and orange.
After deposition, slow-moving tectonic forces lifted all these rock layers upward, ultimately putting them at the top of the Grand Staircase—an immense sedimentary sequence that stretches south from Cedar Breaks and Bryce Canyon, through Grand Staircase-Escalante National Monument and Zion Canyon, and finally into the Grand Canyon. Younger roc …