Unraveling Anza-Borrego’s Ancient Rock Circle Mystery

Just a couple of hours east of San Diego, a profound mystery awaits in Anza-Borrego Desert State Park. Hundreds, possibly thousands, of ancient rock circles dot the vast landscape, baffling archaeologists and hinting at a rich, untold past right in our backyard.

Discovering Anza-Borrego’s Enigmatic Circles

Anza-Borrego Desert State Park, California’s largest state park spanning over 600,000 acres, holds a secret that continues to puzzle experts. Scattered across its remote terrain are countless ancient rock circles, their purpose lost to time.

These intriguing man-made formations, primarily found on rocky terraces and ridges, typically measure 8 to 10 feet across. They are carefully constructed from small, hand-placed rocks ranging from 4 to 10 inches in size. Some circles appear in clusters, while others stand in solitary formation, adding to their mysterious layout.

The sheer volume of these structures is astounding. According to Hayley Elsken, associate state archaeologist for the Colorado Desert District of California State Parks, an archaeologist in the 1980s estimated around 500 circles within a mere 9 square miles. Considering the park’s immense 935-plus square miles, the total number across the desert could easily reach into the thousands.

Theories and Tribal Connections

While the exact age and specific purpose of these rock circles remain elusive, experts firmly agree on their Native American origin. The entire Anza-Borrego area is the ancestral homeland of the Cahuilla, Kumeyaay, and Cupeno peoples, boasting over 4,000 historic sites including villages, hunting grounds, and areas for food processing.

The highest concentration of these rock circles lies in the southern part of the park, an area largely associated with the Kumeyaay. These archaeological sites are protected by law, emphasizing the importance of leaving them undisturbed. Park officials note that the circles are not visible from designated trails, underscoring their remote and preserved nature.

Over the last century, archaeologists have proposed various theories to explain the circles. Suggestions include temporary camping areas, ritual sites, or even large-scale ground art known as geoglyphs. One popular idea is that they served as “sleeping circles,” where Indigenous hunters would clear away rocks to create smooth, temporary resting spots. However, this theory raises a compelling question: why would so many be needed if they were solely for sleeping?

Unlike traditional habitation sites that reveal multiple layers of artifacts and evidence of occupation, excavation efforts for Anza-Borrego’s rock circles have yielded little. There’s a notable absence of stratigraphy (layers of soil and materials), signs of fire, or significant artifacts, making it difficult to pinpoint their function definitively. This lack of conventional archaeological clues is precisely what deepens the mystery.

Anza-Borrego’s Ancient Past

Whatever their ultimate purpose, these rock circles stand as a powerful reminder of the land’s profound and ancient history. Tribal narratives speak of presence “since time immemorial,” with archaeological evidence for human activity in the area dating back at least 10,000 years. As archaeologist Hayley Elsken notes, “We always say with archaeology, you only know what you find, right? So people could have been here much longer, and we just haven’t found that evidence yet.”

This park’s past extends even further. Some 20,000 years ago, long before its colonial naming after Spanish explorer Juan Bautista de Anza and the Spanish word for bighorn sheep, “borrego,” this desert was a starkly different landscape. It was home to mammoths and bison, suggesting a once-grassy plain fed by river valleys. If the rock circles indeed date back this far, they might have been positioned above these ancient rivers, though this remains speculative.

Cultural anthropologist Michael Wilken-Robertson, author of “Kumeyaay Ethnobotany: Shared Heritage of the Californias,” highlights the “different migrations, movements of people” throughout the region’s history. He describes the diverse Kumeyaay lands, stretching from Southern California into the Baja peninsula, where resources like plentiful desert agave were crucial for food, medicine, and ceremonies. Environmental shifts, including the periodic formation of Lake Cahuilla in the desert basin (where the Salton Sea is now), created fertile periods that would have made the area a desirable place to live for hundreds, if not thousands, of years.

The constantly changing environment over millennia adds another layer to the enigma of the rock circles. Pinpointing the exact landscape at the time of their creation is incredibly challenging, making their context even harder to decipher.

Unique to the Colorado Desert

While rock circles exist in other regions, Elsken notes that the particular style found in Anza-Borrego is unique to the Colorado Desert. Other areas often show clear signs of habitation associated with their circles, which is notably absent here. The lack of depth, fire pits, or artifacts means these circles don’t fit typical archaeological profiles of dwelling or activity sites, making them a one-of-a-kind puzzle for those studying our local history.

Frequently Asked Questions About Anza-Borrego’s Rock Circles

• What are these rock circles?
  They are ancient, man-made circular formations of small stones, typically 8 to 10 feet in diameter, found on terraces and ridges within Anza-Borrego Desert State Park.
• Who made them?
  Archaeologists confirm their origin is Native American, likely by the ancestral peoples of the Cahuilla, Kumeyaay, and Cupeno tribes who inhabited the region.
• What was their purpose?
  Their exact purpose remains a mystery. Theories range from temporary sleeping areas or camping spots to ritual sites or geoglyphs, but none are definitively proven due to a lack of supporting archaeological evidence like artifacts or fire pits.
• How old are they?
  Their precise age is unknown, but human presence in the area dates back at least 10,000 years, and possibly much longer, suggesting they could be exceptionally ancient.
• Can I visit them?
  The rock circles are typically in remote areas, not visible from main trails, and all archaeological sites in the park are protected by law. It’s crucial to leave them undisturbed if you ever encounter one.

For those of us in the San Diego area, Anza-Borrego Desert State Park offers a unique connection to an ancient and still mysterious past. These rock circles serve as a powerful, silent testament to the Indigenous peoples who shaped this land for millennia, inviting us to contemplate their ingenuity and respect the enduring secrets they left behind.

Anza Borrego Ancient Rock Circle Mystery