The Lost Elephant Tree
San Diego’s Great Desert Hunt of 1937
Greg Ross
CEO / Owner - Nancy's Vacation Rentals
For years, people whispered about a strange tree hiding somewhere in San Diego County’s desert. Scientists weren’t even sure it was really there. Then, in 1937, a discovery launched an extraordinary search into what is now Anza-Borrego Desert State Park.
Some San Diego stories begin with a building.
Some begin with a person.
This one begins with a tree that people could not seem to find.
For decades, prospectors, naturalists and desert travelers told stories about an unusual thick-trunked tree growing somewhere in the remote desert of eastern San Diego County.
It didn't look much like the plants normally associated with the region.
It had a swollen trunk, twisting branches and a strange sculptural appearance.
It was known as the elephant tree.
There was only one problem.
Scientists couldn't reliably find it.
The Mysterious Tree of the San Diego Desert
The elephant tree, scientifically known as Bursera microphylla, is much more commonly associated with the deserts of Baja California and northwestern Mexico.
Finding it naturally growing in San Diego County placed the species near the northern edge of its known range.
That alone made it interesting to botanists.
But by the early 20th century, there was another problem:
People said the tree was out there.
But nobody seemed able to consistently relocate it.
An Earlier Sighting Was Lost
There were reports of an elephant tree being seen in the San Diego desert as early as around 1911.
But in an era without GPS coordinates, digital maps or satellite imagery, knowing that someone had once encountered a strange tree somewhere in the desert wasn't particularly helpful.
The location was effectively lost.
Over time, stories continued to circulate.
Prospectors and desert travelers reported seeing unusual trees in the region.
But botanists wanted something more reliable than stories.
They wanted proof.
Then Came 1937
In January 1937, two men went looking.
Dr. E. M. Harvey of the U.S. Department of Agriculture and Palm Springs naturalist Don Admiral ventured into the Borrego Desert searching for the elusive tree.
And this time, they found it.
The specimen was positively identified as an elephant tree.
After years of uncertainty, San Diego County's mysterious desert tree was no longer merely a rumor.
But One Tree Raised an Even Bigger Question
Finding a single elephant tree didn't settle the matter.
It created another mystery.
Was this one isolated survivor?
Or was there an entire population hidden somewhere in the rugged desert?
Later that same year, an organized expedition set out to find the answer.
San Diego Organized an Elephant Tree Hunt
The search wasn't simply a few adventurous hikers wandering through the desert.
The expedition included people associated with major scientific and public institutions.
Participants included members of the San Diego Natural History Museum, California state parks officials, and prominent local scientists.
Among those connected to the search was Guy Fleming, an important figure in the development of California's state park system, as well as Harald Sverdrup, director of the Scripps Institution of Oceanography.
The group headed into the rugged landscape around the Vallecito Mountains.
They were looking for more elephant trees.
They found far more than expected.
They Found 75 Elephant Trees
The expedition reportedly documented approximately 75 elephant trees growing on the rocky desert slopes.
That discovery changed the story completely.
The elephant tree wasn't simply a botanical oddity represented by a single mysterious specimen.
There was a real population surviving in San Diego County's desert.
For naturalists, it was an important confirmation of the plant's range.
For everyone else, it was a wonderfully strange story.
A tree that had practically become a desert legend had suddenly been rediscovered in numbers.
“If It Bleeds Red, You Can Be Sure”
One of the best descriptions of the elephant tree hunt appeared in the November 1937 issue of Desert Magazine.
Writer Lillian Bos Ross described traveling into the desert in search of the newly rediscovered tree.
She was given a memorable piece of advice for identifying it:
“If it bleeds red, you can be sure!”
That strange description referred to the tree's reddish resin and bark.
Ross and her husband headed into the desert near Fish Creek.
The trip quickly turned into a classic 1930s desert adventure.
Their vehicle repeatedly became stuck in deep sand.
Eventually they left it behind and continued on foot.
They were searching for a plant that only months earlier had seemed almost mythical.
Why Is It Called an Elephant Tree?
The name becomes obvious once you see a mature specimen.
Elephant trees develop thick, swollen trunks and heavy twisting branches.
Their sculptural forms can resemble the legs or body of an elephant.
The trees also have very small leaves, which help them conserve water in one of the driest environments in Southern California.
Unlike the towering trees found in San Diego's coastal neighborhoods, elephant trees grow slowly and compactly.
Their thick trunks help store moisture.
They look almost designed for survival.
And in a way, they are.
A Survivor at the Edge of Its Range
The elephant tree is better known from Baja California and the Sonoran Desert farther south.
That makes San Diego County's population particularly interesting.
The trees here exist near the northern edge of the species' natural range.
They survive in extremely hot, rocky and dry terrain where annual rainfall can be very limited.
That environment helps explain why the trees remained hidden for so long.
These weren't plants growing beside highways or in easy-to-reach valleys.
They occupied rugged desert slopes and isolated washes that could be difficult to access even today.
In 1937, finding them was a genuine expedition.
What Is Anza-Borrego?
Today, much of the landscape associated with this story lies within or near Anza-Borrego Desert State Park.
The park protects more than 600,000 acres of desert wilderness in eastern San Diego County.
It's California's largest state park.
Visitors come for wildflowers, slot canyons, palm oases, badlands, wildlife, dark skies and some of the most dramatic desert scenery in Southern California.
But hidden among all that scenery is another attraction:
the descendants and surviving relatives of the trees that triggered San Diego's great elephant-tree hunt.
You Can Still Follow the Elephant Tree Story Today
Modern visitors can explore the general area on the Elephant Trees Trail in Anza-Borrego.
The trail lies in the southern portion of the park near Split Mountain Road.
It's not a manicured urban walking path.
The landscape is dry, rocky and exposed.
Depending on road conditions, reaching the trailhead may involve traveling on unpaved roads, and higher-clearance vehicles can be helpful.
Visitors should always check current park and road conditions before heading into the backcountry.
But the Famous Tree Is Gone
There's one bittersweet ending to the story.
The elephant tree that became the famous destination associated with the trail eventually died.
So today's hikers aren't necessarily walking out to see the exact same celebrated specimen that fascinated visitors decades ago.
But that almost makes the trail more interesting.
The landscape remains.
The history remains.
And other elephant trees continue to survive in the desert.
You are essentially walking through the same environment where botanists once searched for a plant they weren't even certain still existed.
Imagine Searching for It in 1937
It's easy to underestimate how different desert exploration was nearly 90 years ago.
No GPS.
No Google Maps.
No satellite phone.
No detailed online trail reports.
No air-conditioned four-wheel-drive SUV filled with electronic navigation systems.
Instead, explorers relied on paper maps, handwritten directions, local knowledge and their ability to recognize landmarks.
Vehicles became stuck.
Roads disappeared.
Water had to be carried.
And the desert was enormous.
Finding a particular tree could actually be an adventure.
San Diego's Desert Has Its Own Hidden History
Most visitors think of San Diego as a coastal destination.
Beaches.
Palm trees.
Mission Bay.
La Jolla.
Coronado.
But drive east for a couple of hours and the landscape changes completely.
The ocean disappears.
The mountains rise.
Then suddenly you descend into one of the most remarkable desert environments in California.
And hidden among those rocks and canyons are stories many San Diegans have never heard.
The Lost Tree That Wasn't Lost After All
That's what makes the elephant tree story so appealing.
It isn't about treasure.
It isn't about a ghost town.
It isn't even about a person.
It's about curiosity.
A strange tree had been reported somewhere in the desert.
Its location disappeared.
Scientists wondered whether the stories were accurate.
Then, in 1937, people went looking.
They found one.
Then they found dozens more.
And a botanical mystery became another remarkable chapter in San Diego County history.
Nearly 90 years later, you can still travel into the desert and follow their footsteps.
Frequently Asked Questions
What is an elephant tree?
The elephant tree, Bursera microphylla, is a desert plant with a thick swollen trunk, twisting branches and very small leaves. It is native primarily to parts of Baja California, Sonora and the desert Southwest.
Why is it called an elephant tree?
The tree's thick trunk and heavy sculptural branches can resemble the legs or body of an elephant.
Were elephant trees really “lost” in San Diego?
There had been earlier reports of elephant trees in San Diego County, but exact locations were difficult to verify. In 1937, researchers successfully located and positively identified specimens in the Borrego Desert.
What happened during the 1937 elephant tree expedition?
After an elephant tree was located early in 1937, a larger scientific expedition searched the surrounding desert and reportedly documented approximately 75 elephant trees in the Vallecito Mountains area.
Where can you see elephant trees in San Diego County?
Elephant trees can still be found in parts of the Anza-Borrego desert. The Elephant Trees Trail provides access to an area historically associated with the species.
Can you visit the Elephant Trees Trail today?
Yes, although visitors should check current Anza-Borrego Desert State Park conditions before traveling. Some access roads may be unpaved or rough, and desert temperatures can become dangerous during warmer months.
When is the best time to visit?
Late fall through early spring is generally the most comfortable period for exploring the Anza-Borrego desert. Summer temperatures can be extreme, so desert hiking requires careful planning, adequate water and weather awareness.
Discover the San Diego Most Visitors Never See
San Diego's history doesn't end at the coastline.
Some of its most surprising stories are hidden in mountains, canyons and desert landscapes that visitors rarely associate with America's Finest City.
At Nancy's Vacation Rentals, we've spent more than 25 years helping guests experience San Diego and the surrounding region.
Our San Diego Uncovered series explores the forgotten landmarks, unusual stories, hidden places and local history that make this corner of Southern California so fascinating.
Because sometimes the best adventure isn't finding something new.
It's rediscovering something people almost forgot.
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The Lost Elephant Tree: San Diego’s Great Desert Hunt of 1937
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In 1937, scientists ventured into San Diego County's desert searching for a mysterious elephant tree many believed had been lost. Discover the incredible Anza-Borrego expedition that found dozens of them.
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