Trestles Beach

Trestles Beach is the cobblestone shoreline at San Mateo Point, where San Mateo Creek reaches the ocean at the northern end of San Onofre State Beach. The name comes from the railroad trestle that carries the tracks over the creek behind the sand. The Orange and San Diego county line crosses the point, putting the beach in San Diego County with the San Clemente bluffs immediately north of it in Orange County. Surfers split the stretch into breaks named from north to south, Cottons and Uppers above the trestle and Lowers and Middles below it. California State Parks has managed the land since 1971 under an agreement with the Navy, which holds it as part of Marine Corps Base Camp Pendleton, and the Trestles Wetlands Natural Preserve sits behind the beach along the lower creek.

The bottom is what separates this beach from the sand beaches on either side of it. San Mateo Creek carries rounded cobblestone down to the point, and that cobble forms a shallow reef the swell trips over rather than a plain sand bar. The cobble makes the inshore bottom a rocky reef biome, and the waves breaking across it put a surf zone biome directly on top, with no kelp canopy growing on the stones. Farther out the picture changes. About half a mile offshore, in 38 to 50 feet of water, the southern end of Wheeler North Reef begins at San Mateo Point and runs roughly 2.5 miles north to just above San Clemente Pier. Southern California Edison built that boulder reef to replace kelp lost to cooling-water discharge from the San Onofre Nuclear Generating Station, beginning with a test reef in 1999, and giant kelp now grows across it. That adds a kelp forest biome, though it sits well offshore and divers reach it by boat rather than from the sand.

Surfing accounts for most of the activity here, and the consistency of the wave is why Trestles Beach will host the surfing events at the 2028 Los Angeles Olympics in July of that year. Surf fishing works the sand pockets between the cobble, and swimming is common through the summer. Shore diving and spearfishing stay uncommon, because the inshore cobble holds little relief and the real structure is the artificial reef half a mile out, which is a boat trip rather than a swim.

No road reaches the beach. Most people walk in on the Trestles Beach Trail from the corner of South El Camino Real and Cristianitos Road in San Clemente, a paved and dirt path of roughly 1 mile that passes under Interstate 5 and follows the creek corridor down. Parking is free on the street near the trailhead or paid in the lot at the intersection. No marine protected area covers this stretch of coast, so fishing and spearfishing are legal under standard California regulations.