Tejon Pass is a Journey Through Time, Terrain, and Tectonics

There’s a drive that I’ve done many times where I tend to look around and wonder about the place. It’s while I’m on I-5 headed north, a while after passing Santa Clarita, Magic Mountain (I always strain to see if there are people on the roller coasters), and the CalArts up on the hill (where so many Pixar legends once trained).

Perhaps you’ve done it, too. Maybe you get gas in Castaic, then you pass Pyramid Lake, and you’ve fully left the San Fernando Valley behind. Then the climb begins and the terrain changes dramatically. It’s subtle at first. The road starts to rise, winding past low ridges covered in golden grass and sun-bleached rock. Then the grade steepens. You see warning signs for trucks: “Turn off A/C to avoid overheating.” Semis tuck into the right lanes, their flashers blinking, straining against gravity. You’re ascending into the Tehachapi Mountains. The name comes from the Southern Paiute word “Tihachipia” meaning “hard climb”, which makes a ton of sense when you’re there. These mountains are part of the geologically fascinating Transverse Ranges, which we’ve written about before. Up ahead is Tejon Pass, the official name for the mountain crossing, but it’s more famously known to most drivers as the Grapevine, the steep stretch of I-5 that descends into the Central Valley.

The highway carves through steep canyon walls and hillsides sometimes bright with flowers, sometimes scarred by past wildfires. If it’s summer, the air gets drier and hotter; in winter, it might be raining or even snowing. You’re crossing one of the most weather-vulnerable stretches of highway in the state. The road is wide but unforgiving. Watch for crosswinds, or the occasional patrol car tucked into a turnout. Tejon Pass is more than just a mountainous pathway connecting the San Joaquin Valley to Los Angeles. It’s a geological and historical hotspot that tells a story of native tribes, daring transportation, seismic activity, and human ingenuity.

Rising to an elevation of 4,160 feet, Tejon Pass’s unique topography is a fascinating blend of rugged mountains, deep canyons, and expansive plateaus. At the summit, the land briefly levels out. There’s a moment where the mountains give you a glimpse in both directions. Behind, the tangled ridges of Southern California. Ahead, a vast, hazy bowl: the southern end of the Central Valley. You pass the Fort Tejon Historical Park turnoff, and suddenly, you’re descending.

The road plunges down in a series of long, controlled curves. Runaway truck ramps cut into the hillside like scars. Then, like stepping through a door, you’re out of the mountains. Flatness stretches to the horizon. Orchards, oil derricks, and cattle fields mark your arrival in the valley. The air feels different. Denser, warmer. You’re in Kern County now, approaching the outskirts of Bakersfield, and the Grapevine is behind you. It’s as if you crossed an invisible line, a border between two Californias.

Perhaps one of the most captivating aspects of Tejon Pass is its seismic significance. The region is situated at the intersection of two major fault lines: the San Andreas Fault and the Garlock Fault. This combination has made the area a hotspot for seismic activity and has resulted in a number of substantial earthquakes over the years.

The most significant of these occurred in 1857, with an estimated magnitude of 7.9. Known as the Fort Tejon earthquake, it caused a rupture along the San Andreas Fault, leaving a lasting imprint on the landscape. Although the area was sparsely populated at the time, the quake’s impacts were far-reaching and could be felt as far as Las Vegas. The event is a reminder of the LA region’s seismic vulnerability, spurring modern research and monitoring to understand and mitigate future risks.

Long before European contact, Tejon Pass was a vital passageway for several Native American tribes, including the Chumash and Tataviam. The area around present-day Gorman, near the pass, was home to the Tataviam village of Kulshra’jek, which functioned as a significant trading crossroads for centuries. These Indigenous communities recognized the strategic importance of the pass, utilizing it for travel, trade, and communication across regions.

With the arrival of European settlers, the pass continued to play a vital role in California’s development. It became one of the state’s oldest continuously used roadside rest stops, a title it still holds today. The pass has borne witness to the evolution of transportation, from horse-drawn carriages to modern highways.

However, not all the tales from Tejon Pass are picturesque. The area has earned the foreboding nickname “Dead Man’s Curve.” This name references a notoriously dangerous curve on the old Ridge Route, infamous for its high number of accidents. The treacherous curve became symbolic of the broader challenges of early automotive travel through the mountains, where both engineering and human limitations were tested.

The Ridge Route, completed in 1915, was California’s first paved highway directly connecting the Los Angeles Basin with the San Joaquin Valley. Engineered to traverse the challenging terrain of the Sierra Pelona Mountains, it followed a winding path from Castaic to Gorman, culminating at Tejon Pass. This innovative route was a significant milestone in California’s transportation history, facilitating automobile travel between Southern and Central California. ​

A notable segment of this route is known as “The Grapevine,” located in the northern portion descending into the Central Valley. The name originates from the Spanish term “La Cañada de las Uvas,” meaning “The Canyon of the Grapes,” a reference to the wild grapevines that early Spanish explorers, including Don Pedro Fages in 1772, observed growing abundantly in the area.

Over time, the Ridge Route underwent several significant transformations to accommodate increasing traffic and improve safety. In 1933, it was replaced by a three-lane alternate highway, later designated as U.S. Route 99. This was expanded into a four-lane expressway by 1953 . Eventually, the route evolved into the modern eight-lane beast known as the Interstate 5 Freeway, completed in 1970, which continues to serve as a vital artery for transportation in California. You will encounter lots and lots of trucks. ​

Today, Tejon Pass continues to serve as a crucial thoroughfare for Californians and visitors alike, with Interstate 5 traversing the landscape. The Tejon Ranch Conservancy plays a central role in protecting and interpreting this remarkable landscape. Established as part of a landmark 2008 conservation agreement, the Conservancy is tasked with stewarding over 240,000 acres of permanently protected land—making it one of the largest private conservation efforts in California history. Its mission goes beyond preservation; the Conservancy offers guided hikes, wildlife tracking programs, and educational outreach that invite the public to engage directly with the land.

Soon, however, you leave Tejon Pass behind and continue north on I-5, dropping into the southern end of the Central Valley. You pass through the outskirts of Buttonwillow and Lost Hills, where the landscape flattens into a broad, arid plain. It’s mile after mile of industrial agriculture, just endless rows of almonds, pistachios, and oil wells under a hazy sky. The scenery turns monotonous, and although it does have a story (mostly about moving water), it’s one we’ll save for later.

Tejon Pass is one of those places most people barrel through without a second thought. It’s just a steep stretch of I-5 between Los Angeles and the Central Valley, a name on a weather report when the Grapevine closes in winter. But if you take a moment to look beyond the guardrails and gas stations, you’ll find a landscape layered with deep history and surprising complexity. Knowing what lies beneath the pavement won’t make the climb any less steep—but it might make the ride a little more meaningful.