Thousands of drivers cross the 210 freeway near Pasadena every day without knowing what sits below. A concrete flood dam. A rock outcropping shaped like a horned, grinning face. And a location that once hosted some of the strangest rituals in American history, performed by a man who also helped invent modern spaceflight. The folklore calls it a gateway to hell. Real history is stranger than the legend, and it starts with a name most people get wrong.

The name came first, not the devil

Popular legend suggests occultists named the site for its satanic energy. The record disagrees. A judge named the gorge Devil’s Gate in 1858, decades before any ritual, simply because the rock resembled a similar feature he had seen on Sweetwater Creek. Los Angeles County built the region’s first flood control dam here in the 1920s to tame the Arroyo Seco. The devilish profile was a natural quirk of geology, not proof of anything.

Getting that order right matters. The spooky name did not summon the history. That history arrived later and borrowed the name.

A living tradition, told with respect

Long before the dam, the Tongva people knew this gorge. In their traditional narratives, the roaring winter water rushing through the rocks carried the sound of the Coyote spirit laughing. They regarded the site as spiritually charged and treated it with care, mindful of the Coyote’s trickster nature.

This is a living Indigenous cultural tradition, not a ghost tour prop. It is distinct from the occult and paranormal stories that later gathered here.

The rocket scientist who summoned a goddess

Here the history turns remarkable. Jack Parsons was a self taught chemist and rocket engineer who helped found both the Jet Propulsion Laboratory and Aerojet. His solid propellant work genuinely advanced spaceflight. He tested early rockets in the Arroyo Seco. By night, he practiced ceremonial magic as a follower of occultist Aleister Crowley.

In early 1946, Parsons and a young science fiction writer named L. Ron Hubbard performed a series of rituals they called the Babalon Working. Their stated goal was to invoke a goddess into the world. They carried out parts of the working near the Arroyo, and occult lore credits, or blames, those rites for opening a permanent channel at Devil’s Gate. Every part of Parsons, Hubbard, JPL, and the rituals is historically documented. Only the open portal is folklore.

Tragedy and the stories that followed

In the 1950s, several children vanished in the surrounding watershed. Local legend tied the disappearances to the supposed open portal. The documented truth is grimmer and fully human. Investigators later linked cases in the area to a convicted child killer named Mack Ray Edwards. The portal story is folklore. The crimes were real.

The reported phenomena

Visitors near the dam describe shadow figures moving through the eucalyptus, disembodied whispers, and a deep laugh echoing from the drainage tunnel. Some report sudden panic and a heavy, oppressive weight upon entering the canyon. Present these as reports and folklore, not verified fact.

How to visit

You can view the dam and the Devil’s Gate rock from the public trails in the Arroyo Seco parkland off the Foothill Freeway in La Canada Flintridge. A heavy iron gate seals the tunnel, and entering it or climbing the dam is illegal and dangerous. The riverbed below hides deep mud, loose rock, and flash flood risk. Stay on the trails.

References & Further Reading

Jack Parsons, Occult Encyclopedia

Devil’s Gate Dam, Occult Encyclopedia

Jack Parsons and the Occult Roots of JPL, Space Safety Magazine