Ponca State Park in northeastern Nebraska features the 'Towers of Time' monument, created by Jay Tschetter and it represents various eras in Earth's past:


The 25-foot tower on the left depicts the late Cretaceous Period (65 million to 99 million years ago) when Nebraska was under water. This was the age of the dinosaurs and displays prehistoric sea and land creatures.


The 27-foot center tower features species from the Pleistocene Period (1.8 million to 10,000 years ago). This was during the Ice Age when woolly mammoths, saber-toothed cats and giant sloths roamed the Earth.


The 25-foot tower on the right features a collection of modern animals, everything from blue herons to buffalo that inhabit the Missouri River region.


The square fountain includes images of indigenous people from the Folsom culture, Paleolithic period, Earth Mound Builders and recent Natives who occupied the region in the 1800s.