Welcome to a Window to the Past...

Loop Wash in Fish Creek. More than 4 million years ago this area was a seashore. Can you see the evidence?


View ancient Anza-Borrego and see the great range of plants and animals that lived here millions of years ago. Today, where you see a desert, was once the shoreline of a great ocean. Over time the ocean transitioned to an inland sea and later a delta formed by the Colorado River. The delta shaped an entirely new landscape of forests, rivers, and lakes. Eventually the area became a great savannah that supported a vast array of Pleistocene plants and animals.

Today the Anza-Borrego Desert has yielded the greatest collection of Pleistocene fossils in North America. Step through the virtual window to see camels, llamas, mammoths, sloths, cats, wolves, bears, and horses...as well as ancient marine life that that ranges from seals to shells.


Before You Go to Anza-Borrego

Discover its ancient past. This site will take you back in time to see pre-historic plants and animals that existed here millions of years ago. On these pages we hope you

  • Learn about the pre-history of ancient Anza-Borrego and the record of life that goes back over 45 million years. This area has the greatest collection of Pleistocene mammal fossils found anywhere in North America.
  • Study the clues of the fossil record to solve the mysteries of what plants and animals existed here in the past.
Experience the awesome wonder of ancient and worlds that existed here millions of years ago.

Start Your Journey Here


Your journey to the past starts on the left at Loop Wash in Fish Creek. Today you'll find the remains of an ancient sea that supported a great range of marine life.

· Pan the scene by holding down the left button of your mouse (or the only button on a Mac) and then click the hot spots to travel deep into ancient Anza-Borrego.
Then delve deeper into this site to learn more about how scientists, rangers, park personnel, and volunteers are uncovering clues to ancient worlds.