Closeup photo of a fossilized seashell, Painted Gorge

Fossilized Sea Shell in Painted Gorge


At least two things are readily apparent in the southern reaches of Anza-Borrego. One is that this area was clearly under water at one time, both sea water from the Gulf of California and fresh water and mud from the Colorado River. There is ample evidence in the character of the soil and in fossilized sea shells and petrified wood. Another as the northwest trending of ranges like the Coyote Mountains shows, is that the land is slowly moving northwest toward San Francisco.

You can see this from a distance by stopping at the Carrizo Badlands Overlook. There is further evidence when you drive into Fossil Canyon, Painted Gorge, or the Yuha Basin and examine not only the land formations but look for fossilized sea shells.

What may be less obvious is that volcanoes once erupted. The Volcanic Hills, accessed along Jojoba Wash and Montero Wash, and Painted Gorge are good places to study the unique characteristics of the volcanic soils of the Alverson Formation.

For over a century, paleontologists have swept over this region, discovering the fossilized remains of distinct animals, and developing a remarkable picture of life here over the past millions of years. Suffice it to say that the verdant Anza-Borrego of old was quite different from the arid Anza-Borrego of today.