DTP - 001 The Deep Time of Perris Lake

Evidence, Scale, and Why This Section Exists

The Path Behind is not a straight line. It is not a sequence of arrivals, replacements, or progressions moving cleanly from past to present. It is a layered record of presence—geological, biological, and human—accumulated unevenly across deep time.

Understanding that record requires paying attention to different kinds of evidence preserved at different depths and timescales. Two disciplines that make this possible are paleontology and archaeology. Though often treated separately, both are concerned with how life interacted with land in the past, and both rely on what remains embedded in the ground to reconstruct that relationship.

Paleontology looks at deep biological time: fossils, extinct species, and the environments that sustained them long before modern human societies. Archaeology focuses on human presence—how people lived, moved, and remained within a landscape through material traces. The distinction between them is less about subject than scale. Paleontology works across hundreds of thousands or millions of years; archaeology operates within the far shorter span of human history.

In places where landscapes preserve long, continuous records of life, those scales overlap. Southern California is one such place. During my time in the region, I visited the San Diego Natural History Museum and spent time with the Cerutti Mastodon exhibit. What stood out was not spectacle or certainty, but restraint: the careful presentation of evidence, the acknowledgement of uncertainty, and the quiet way a fossil site was used to open a much larger question about time, land, and preservation. I am not an expert in paleontology or archaeology. I found the connection interesting, and worth following.

What follows is not history in the conventional sense, and it is not an argument. It does not assume that time proceeds neatly or that earlier evidence must explain what comes later. Instead, it explores how paleontology and archaeology, read together, expand our understanding of how long this land has been capable of sustaining life—and why that deep environmental history matters when thinking about later human presence.

In this context, a fossil discovery is not a challenge to Indigenous history. It is part of the deeper record of the land itself. The Cerutti Mastodon site is included here because it illustrates how deep time and human history intersect in this region, and why the ground beneath modern culture carries far more history than is immediately visible.

Disruptive Evidence: The Cerutti Mastodon Site

Near present-day San Diego, excavations at the Cerutti Mastodon Site uncovered the remains of an American mastodon dated to approximately 130,000 years before present. The bones displayed spiral fractures—patterns associated with breakage while fresh—and large stones found in direct association appeared positioned and worn in ways suggesting deliberate use rather than random geological damage. No human remains were recovered. No shaped tools were identified. The interpretation rests on the relationship between fractured bone, stone placement, and burial context.

The site dates to the Late Pleistocene Epoch, specifically the Last Interglacial period (Marine Isotope Stage 5e). This was a warm interval between major ice ages, marked by higher sea levels, more active river systems, and expanded wetlands across much of Southern California. Whatever occurred at Cerutti took place in a landscape that no longer exists.

The implications of the site are notable, but limited. If the interpretation is correct, it suggests that intelligent beings may have interacted with this terrain far earlier than most accepted migration models allow. The claim remains controversial, and appropriately so. Critics argue that natural proc

esses or later disturbance could account for the fractures. Proponents counter that the evidence is internally consistent and occurred prior to burial. What matters here is not which interpretation ultimately prevails, but what the site represents: a reminder that the land does not always conform to simple, linear timelines.

Importantly, this evidence does not establish ancestry, migration routes, cultural continuity, or identity. It suggests only the possibility of an isolated interaction between intelligence and landscape—one that left no known descendants and no sustained presence.

Deep Time: What This Land Was Then

During the Late Pleistocene, Southern California was markedly different from today. Coastlines lay farther inland, seasonal water was more reliable, and basins and terraces functioned as ecological corridors rather than engineered infrastructure. Grasslands and wetlands supported large herbivores such as the American mastodon (Mammut americanum), which ranged across much of North America until their extinction roughly 11,000 years ago, near the close of the Pleistocene.

That extinction coincides with the transition into the Holocene Epoch, the geological interval that contains all known human civilizations. The Cerutti mastodon lived more than 100,000 years before that transition, in a world shaped by different plant communities, climate regimes, and patterns of movement. Southern California at that time was biologically productive and repeatedly capable of sustaining large life forms across multiple climate cycles.

This deep environmental continuity is what makes fossil discovery meaningful here. Paleontology establishes the long-term habitability of the land: water, vegetation, and terrain capable of sustaining life well before modern conditions emerged.

Human Presence as Layers, Not Successions

By at least 12,000–13,000 years ago, humans were firmly established in Southern California during the early Holocene. Over time, Indigenous cultures developed durable relationships with specific places, adapting to climatic shifts while maintaining continuity of presence. Groups such as the Cahuilla are understood to have emerged as a distinct cultural community approximately 2,000–3,000 years ago, drawing on much deeper Indigenous occupation in the region.

Their history is not defined by a single moment of arrival, nor does it require validation through deep-time fossil evidence. It is defined by endurance: sustained ecological knowledge, seasonal movement, trade networks, and stewardship maintained across generations.

The Cerutti Mastodon site does not extend Indigenous history backward in a genealogical or cultural sense. Instead, it extends the timeline of the land itself. It shows that the same terrain later inhabited by Indigenous peoples had already sustained life through earlier climate regimes, extinction events, and environmental transformations.

These forms of evidence occupy different categories. The Cerutti site proposes presence without continuity. Indigenous histories demonstrate continuity without requiring deep-time claims. They are not competing narratives. They are separate layers preserved in the same ground.

Paleontology and Archaeology as Linked Records

In Southern California, paleontology and archaeology are naturally linked because they are preserved in the same physical archive. Fossils document what the land could sustain over deep time. Archaeology documents how people learned to live within landscapes that had already proven capable of supporting life for hundreds of thousands of years.

From this perspective, the land is not a backdrop to history but an active participant. Coastlines, basins, uplands, and resource corridors shaped how life moved through space and time. Geological features that preserved fossil remains also structured seasonal movement, settlement patterns, and trade networks thousands of years later.

Modern culture occupies only the thinnest surface layer of this history.

What This Place Teaches

When viewed together, fossils, fractured bones, archaeological traces, and living cultures do not form a single linear narrative. They form a layered record. Some layers are brief. Others endure. What connects them is not ancestry, but geography.

The Path Behind exists to explore that depth without forcing resolution. It uses deep time not to make claims, but to expand perspective—to remind us that the ground beneath our feet carries a history far deeper than competition, performance, or even culture.

References

Paleontology and the Cerutti Mastodon Site

Holen, S. R., Deméré, T. A., Fisher, D. C., Fullagar, R., Paces, J. B., Jefferson, G. T., Beeton, J. M., Rountrey, A. N., & Holen, K. A. (2017). A 130,000-year-old archaeological site in southern California, USA. Nature, 544(7651), 479–483. https://doi.org/10.1038/nature22065

San Diego Natural History Museum. (n.d.).

The Cerutti Mastodon Discovery. Retrieved January 29, 2026, from https://www.sdnhm.org/exhibitions/the-cerutti-mastodon-discovery/

San Diego Natural History Museum. (n.d.). Cerutti Mastodon: Story of the discovery. Retrieved January 29, 2026, from https://www.sdnhm.org/science/consulting-services/paleo-services/projects/cerutti-mastodon/cerutti-mastodon-story-of-the-discovery/

Deep Time, Pleistocene, and Environmental Context

National Park Service. (n.d.). The Pleistocene Epoch. Retrieved January 29, 2026, from https://www.nps.gov/articles/pleistocene.htm

Ruddiman, W. F. (2014). Earth’s climate: Past and future (3rd ed.). W. H. Freeman.

Indigenous History and Southern California Archaeology

Bean, L. J., & Smith, C. R. (1978). Cahuilla. In R. F. Heizer (Ed.), Handbook of North American Indians, Vol. 8: California (pp. 575–587). Smithsonian Institution.

Lightfoot, K. G., & Parrish, O. (2009). California Indians and their environment. University of California Press.

Moratto, M. J. (1984). California archaeology. Academic Press.