WALNUT CREEK, CALIFORNIA – If you spend any time in the East Bay, it’s always just kind of there.
Mount Diablo looms above everything we do. At your kid’s soccer game? The mountain’s right above you. Stuck in traffic on 24? At least you have a pretty backdrop.
People rarely pause to consider the fact that this benign, beautiful presence is literally named “Devil Mountain.”
That’s a little scary. But it turns out the origin story of the mountain’s name is absolutely fascinating, and involves ghost stories, legends, and comical cultural misunderstandings.
Read on!
Multiple local histories trace the name back to a Spanish military pursuit of Native people in the early 1800s.
The story goes that the Native group slipped away into a thick stand of willows near what later became known as Pacheco Slough (in the area of present-day Concord, kind of by Buchanan Field).
In the confusion — and with the thicket seeming to “swallow” people into the dark, perhaps borne away by spirits or ghosts according to the soliders’ telling — Spanish soldiers reportedly began referring to the place as “Monte del Diablo.”
Here’s the key detail: in these accounts, “Monte del Diablo” is tied to the thicket, not the mountain. California State Parks materials explicitly describe “Monte del Diablo” as the name given to a willow thicket near Pacheco Slough.
Turns out that “monte” has two meanings in Spanish. It can indeed mean “mountain,” but also “thicket”.
For decades, the “monte” in “Monte del Diablo” was describing the dense vegetation where the possibly-spirit-assisted escape happened.
Then, though, English-speaking newcomers started to arrive. Lured out west by the Gold Rush and the agricultural bounty of the East Bay, people from all over the world settled in the Diablo Valley.
When they heard Spanish locals refer to “Monte Del Diablo” (the thicket), they naturally assumed those locals were referring to the gigantic “monte” (mountain) that was ever-present on the horizon.
They started calling the mountain “Mount Diablo” in English.
Save Mount Diablo sums it up bluntly: a linguistic accident gave California its “Devil Mountain.” There’s more to the history, though.
Once the phrase was in circulation, it began appearing in official contexts that helped it “stick” — including maps and land grant references connected to the area around present-day Concord.
Today, it’s inextricably tied to the mountain. No one is about to change its name.
But really, the “Devil” (as far as early Spanish soldiers saw it, anyway) is in the thicket by the airport, not on the mountain.
Really, Mount Diablo originally had a totally different name. Long before Spanish expeditions and American mapmakers, the mountain held deep significance for Indigenous communities across the region.
Save Mount Diablo notes that Mount Diablo is known as Tuyshtak, often translated as “dawn of time,” in Ohlone/Chochenyo context.
A Muwekma-related document adds detail, citing linguistic research and interviews recorded by anthropologist-linguist J.P. Harrington in the early 20th century that preserved the placename “Tuyshtak” for Mount Diablo.
Today, that name is even reflected on a “Mount Diablo” street sign in downtown Lafayette.
So the “Devil Mountain” that’s so present in all our lives really originated from a ghost story and a linguistic blunder. And if you want to go back farther–to the origins of the planet, by Ohlone legend–it has a different name entirely.
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