Located in Eastern California, near the mesmerizing Mammoth Lakes, this site, recognized as a national monument since the early 20th century, stands as a prime example of the many geological wonders found across the country and the state. Surrounded by a surreal, idyllic landscape filled with greenery and a massive waterfall, it’s a must-visit destination for outdoor enthusiasts.
About 5 hours north of L.A., Devils Postpile Monument features a unique rock formation: towering hexagonal basalt columns, rising from a cliff wall and geometrically one-of-a-kind due to their near-perfect symmetry. This rare formation is seldom seen in other similar places around the world.
How the columns were formed
According to U.S. Geological Survey, a massive lava flow, probably from the Upper Soda Springs area, descended into the Reds Meadow Valley approximately 100,000 years ago. As the lava cooled slowly and evenly, it contracted, forming vertical cracks that resulted in the formation of the hexagonal basalt columns visible today.
Many thousand of years later, during the last ice age, glaciers advanced over the region, eroding much of the lava mass and leaving behind the polished surfaces atop the columns. The glaciers also left scratch marks on the columns, further enhancing their unique appearance.
The columns are not only strikingly beautiful due to their rare shape that stands out in the wild, but also because of their size. Each column reaches up to 60 feet in height and 1 to 2 feet in width, with the formation stretching roughly 1,000 feet along the cliff.
The mesmerizing Rainbow Falls
Though Devils Postpile is impressive and famous for its basalt columns, that’s not the only thing this natural landmark has to offer. Just a 2.5-mile hike away, Rainbow Falls is the tallest waterfall on the Middle Fork of the San Joaquin River, plunging 101 feet into the pool below.
The waterfall gets its name from the optical illusion created on sunny days, when the mist forms vibrant rainbows, making the falls a magical sight for visitors, as the NPS explains. The waterfall was shaped by the region’s volcanic past, and over time, the river has eroded the softer rock, gradually retreating the falls upstream and sculpting the surrounding landscape.
How to visit Devils Postpile Monument
Devils Postpile is typically accessible only from mid-June to mid-October. Your journey will begin at Mammoth Mountain Main Lodge, where you can purchase tickets for the shuttle bus at the Mammoth Adventure Center.
The shuttle will take you to Reds Meadow Valley, stopping at Devils Postpile. From there, a short trail leads directly to the columns. This year, Reds Meadow Road and the shuttle service are tentatively open only on Saturdays and Sundays until October 6, so it’s important to plan your visit accordingly.