The youngest fossils in the park are less than one million years old, and come from the 14 ancient lake deposits found within Zion. Multiple times in Zion's past, landslides and lava flows have blocked canyon drainages, temporarily damming up the streams to form lakes. Sediments accumulated on the bottoms of these lakes, occasionally preserving evidence of the lifeforms of the time. The lakes are no longer there, but these Quaternary age fossils give us a look into the environments of the region in the recent geological past.
Evidence of terrestrial life has also been uncovered, showing us that modern, diverse life roamed this land over the last 200,000 years. The oldest of these lake sediments contained a rodent skull and bison vertebra (top photo) that date to approximately 220,000 years ago.
Footprints of a stork-like bird (photo at right) and a footprint of a large mammal, such as a camel or elk, have been discovered in the 126,000 year-old sediments of a lake that filled the Coalpits Wash area.
And in lakebed deposits from 1,600 years ago, a Rocky Mountain bighorn sheep forelimb bone has been uncovered—a different subspecies of bighorn than that found in the park today.
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Last updated: July 6, 2015