Dig at Twentynine Palms Marine base unveils artifacts

After a 45-minute ride in a government-issued SUV, bumping along a dusty dirt road into the interior of Marine Corps Air Ground Combat Center in Twentynine Palms, the color and texture of the terrain — predominantly sandy beige, dotted with greenish creosote bushes — changed dramatically.

A prehistoric lava flow — more than a mile long and many football fields wide — covered the area in blackish, odd-shaped volcanic rock, fragments of which had long ago been baked into the ground, creating a hardened surface described, fittingly, as desert pavement.

Scattered amid this otherworldly scene were shards of shrapnel and random artillery ordnance, some spent, some possibly live. The area was used for training before it was determined to be a historically significant site — one of more than 1,800 archeological sites discovered across the 1,100-square-mile military installation.

The lava that encases this massive swath of desert spewed from a nearby volcano about 50,000 to 100,000 years ago, said John Hale, archeologist for the National Resources and Environment Affairs Division at the combat center.

“This predated the arrival of man,” Hale said while striding across the vast rubble field.

The natural resources division, in compliance with federal law, conducts ongoing surveys and evaluations at the combat center.

“It’s a process that’s defined in the National Historic Preservation Act, which requires us to evaluate all the sites on base for national register eligibility,” Hale said.

To date, about 67 percent of the installation has been inventoried for cultural resources and more than 300,000 artifacts have been collected, cataloged and housed at the Archeology and Paleontology Curation Center at the combat center — the only facility of its kind in the Marine Corps.

Most of these artifacts are rocks and stones, including arrowheads and milling slabs, but there are also pottery shards and bones of prehistoric creatures, including a mastodon and horse.

About 10,000 years ago, Native Americans first made their appearance on these lands. The discovery of prehistoric tool-stone quarries, lithic (stone fragments) scatters, habitation sites and rock art provides a glimpse into the lives of its occupants at the time — the Mojave, Serrano, Cahuilla and Chemehuevi Indians.

On Tuesday, two archeologists scratched just below the thin crust of the the rubbly surface, down into the sand, looking for debitage, or thin slices chipped away during the process of fashioning a stone tool from a solid rock.

Tucked into this craggy, moon rock-like rubble beneath our feet were traces of the existence of early man.

“This site was originally surveyed in 1990,” said Scott Kremkau, senior project director for Statistical Research, Inc., as he watched the team scrape and sift a small square section of sand. A scorpion, disturbed by the activity, lurked nearby. “It was originally recorded as a lithics (rock fragment) scatter through here.”

The earlier surveyors also noted, on a crude map drawn up at the time, the presence of prehistoric trail segments — indicated by a few random dots and lines.

The map Kremkau was using contained very few topographical landmarks.

“Unfortunately, this was in the days before GPS’s and their site sketch map is not very detailed and we’ve had a little bit of trouble relocating prehistoric trails,” he said. “They’re very ephemeral little lines through the desert.”

These ancient beaten paths are generally about 30 to 40 centimeters wide and are found in areas that are slightly cleared. He said they should be easy to detect amidst the desert pavement, but, “The site is so large ... things aren’t to scale.”

Locating the lithics scatter also proved to be a challenge.

“It took us all day yesterday to find five pieces,” Kremkau said.

Even to the untrained eye, it was obvious their finds — small, smooth stones — had been manipulated by a crude tool or other object.

Field tech Joseph Woods, a graduate student at Cal State Northridge, held out a small, fairly flat, ruddy-colored fragment about the size of a quarter.

Faint, concentric ripples ran across the surface of one side of this rock “flake” — created when the initial strike was made, breaking this piece off from a rock from which a tool was being formed.

“The pressure (from the strike) goes through and basically pops it off,” he said, describing the process.

He displayed another piece — a thin, orangeish stone about two inches long.

Woods said this type of rock is not found in the area, which makes it a “manuport” — a natural object that’s been moved from its original location by a human.

The Foxtrot Petroglyphs

Not far from where the dig was taking place, the molten lava had flowed over a nearby hillside, stopping at the bottom of what is now a dry river bed, creating a flat-faced rock wall. The earliest humans to visit the area left their marks on these rock panels — like prehistoric graffiti — using pointed rocks or bone tools to peck images into the surface, some resembling humans and animals, but mostly symbols, like squiggly lines or concentric circles.

One of the designs appeared to be Mayan-inspired.

These images, known as petroglyphs, were mostly abstract in form, and although they’ve been extensively mapped, researched and recorded, their precise meanings remain a mystery to archeologists.

A few of the images are pictographs — designs that were painted with pigments made from plants and minerals. This early art form had a spiritual basis.

“Petroglyphs mark portals,” Hale said, pointing to a bighorn sheep figure high up on a rock face. “That’s were the shaman saw the portal into the next world, the spirit world.”

Recognized for its cultural significance, the Foxtrot Petroglyph Site — one of 13 rock art sites discovered on base — was listed on the National Register of Historical Places in 1995, providing federal protection for the ancient artwork.

The area has been off limits to live-fire maneuvers since 1973, but telltale signs of combat training — namely bullet holes — have left their permanent mark on the priceless rock walls.

Through the years, a smattering of Marines have made also left their marks on the wall, some bravely etching their full names into stone. There’s a Depression-era carving — possibly made by a homesteader or miner — with the initials W.F.B., dated May 13, 1933.

Countless other cultural gems have been documented throughout the massive training facility.

In the 1880s, construction of railroads across the Mojave Desert brought miners to its more remote sectors. Like in nearby Joshua Tree National Park, several historical mining districts and abandoned mines are located within the combat center boundaries.

Personal items, including circa World War I-era eyeglasses, eyeglass case, wristwatch and Camel cigarette-brand lighter have been discovered at the base.

The Marine Corps Air Ground Combat Center — the largest U.S. Marine Corps base in the world — hosts the biggest military training program in the nation, where Marines undergo combined arms, live-fire exercises before deploying into combat zones.

Ironically, no prehistoric battle-related objects have been uncovered on the sprawling training grounds.

All the groups living in the area at the time, many millennia ago, may have managed to coexist in peace.

“We have no evidence of warfare at all,” Hale said.

Denise Goolsby is The Desert Sun’s columnist for history and profiles. She can be reached at Denise.Goolsby@DesertSun.com and on Twitter @DesiseGoolsby