📍 Southern California｜Exploring the Mormon Rocks at Cajon Pass

📍 Cajon Pass is located in San Bernardino County, Southern California, forming the boundary between the San Gabriel Mountains and the San Bernardino Mountains. Both ranges are part of the Transverse Ranges of Southern California, shaped by the activity of the San Andreas Fault and related fault systems. This fault is a right-lateral strike-slip transform fault, serving as one of the tectonic boundaries between the North American Plate and the Pacific Plate—a classic example of a transform plate boundary. 🏔️🌋 ⛰️ To the south of Cajon Pass lies the San Bernardino Valley, while to the north lies the Victor Valley (part of the Mojave Desert). Cajon Pass is a critical transportation corridor in Southern California, with multiple railways and highways passing through. Among them, Interstate 15 (I-15) is the most important route connecting Greater Los Angeles and San Diego to Las Vegas. Additionally, the Pacific Crest Trail also traverses this area. 🚗🛤️ 📍 Mormon Rocks are located near the intersection of State Route 138 (SR 138) and Lone Pine Canyon Road in Cajon Pass. They are easily recognizable when driving along I-15. The rocks were named after the Mormon pioneers who passed through the area in the 1850s on their way to establish a settlement in San Bernardino. 👣📜 🪨 Mormon Rocks are actually composed of conglomerate and conglomeratic sandstone. According to the U.S. Geological Survey, they belong to the Cajon Valley Formation, Unit 2, which dates back to the Middle Miocene epoch (beginning 23 million years ago and ending 5.33 million years ago). In the photos, you can see the rocks forming a hogback ridge—a result of tectonic tilting caused by plate movement. The San Andreas Fault runs about 2 kilometers southwest of the rocks, through Lone Pine Canyon, placing Mormon Rocks on the North American Plate side of the boundary. The formation also features numerous tafoni (weathering pits), which serve as nesting spots for various wildlife. 🦅🐾 🧗 The area is popular among rock climbers, while casual visitors can enjoy the Mormon Rocks Interpretive Trail (6W04), maintained by the U.S. Forest Service. Unfortunately, the Mormon Rocks Viewpoint parking area and nearby roadsides are often littered with trash—a reminder to pack out what you pack in! 🚯♻️ Have you visited Cajon Pass or hiked among the Mormon Rocks? What was your experience like? Share your stories or tips below! 👇🗺️ #CaliforniaTravel #CaliforniaTourism #USATravel #ExploreUSA #GeologyRocks #HikingTrails #NatureLovers #OutdoorAdventure #SouthernCalifornia #RoadTripUSA #LandmarkExploration #DesertLandscape