Entry No. 63 — the Los Angeles file — filed under: ruins
Big Horn Mine
Discovered in 1891 by prospector Charles Tom Vincent, the Big Horn Mine was once the largest gold mining operation in Los Angeles County. Its iconic multi-story wooden stamp mill, perched on the slopes of Mount Baden-Powell, was devastated by the 2024 Bridge Fire. Today, the site consists of charred structural ruins, rusted machinery, and gated underground tunnels accessible via a scenic mountain trail.
The story
In 1891, a reclusive hunter named Charles "Tom" Vincent stumbled onto a rich vein of gold high up on the sheer eastern face of Mount Baden-Powell. What grew out of his claim became the largest gold mining operation in Los Angeles County. Miners carved out thousands of feet of subterranean shafts and constructed a massive, multi-story wooden stamp mill directly onto the cliffside to crush the ore before hauling it down the mountain.
For well over a century, that weathered timber superstructure hung on against alpine winds and heavy winter snows, slowly decaying into LA's most dramatic industrial ghost site. Then the Bridge Fire swept through the Angeles National Forest in September 2024. The blaze gutted the historic stamp mill, leaving behind a stark landscape of burned posts, collapsed corrugated tin, and iron machinery frozen on the mountain slope.
What remains today isn't a manicured historical monument—it's a raw, charred footprint of early California extractivism. You walk among fire-blackened structural remnants, twisted iron gears, and heavy steel grates sealing off the dark tunnel portals where cold, damp air bleeds out from deep inside the mountain.
What it's like
The journey begins at the Vincent Gap parking lot along Highway 2, following a four-mile round-trip trail cut into the mountainside. The post-fire landscape offers raw, wide-open views into the San Gabriel backcountry, but shade is virtually nonexistent now. When you reach the mine site, stay on solid ground—the fire left the remaining structural timbers brittle and hazardous. You can peer through the iron gates welded over the mine shafts to feel the draft pouring from the tunnel mouths, but under no circumstances should you try to force entry or scramble across the loose debris fields.
The move: Hike the 4-mile round-trip trail from Vincent Gap to photograph the historic ruins and take in sweeping views of the San Gabriel Mountains.
📍 Before you go While the hiking trail is on public land in the Angeles National Forest, the mine tunnels are gated off by the Forest Service, and the remaining stamp mill ruins are structurally unstable after being burned in the 2024 Bridge Fire.
- 📍 Azusa
- 💸 Free
- ⚡ Low-key
- 🌗 Outdoors
Where: Azusa, CA 91702, USA
Hours: Added 2026-07-20 — confirm current access before you go.
Pair it with
- Emma Mine — Compare the scorched high-altitude ruins of Big Horn with another late-19th-century gold and copper ghost site tucked into the mountain slopes of Acton.
- Mount Wilson Observatory 60-inch & 100-inch Public Ticket Nights — Pair a daytime trek through industrial ruins with a nighttime look through giant century-old telescopes on another ridge of the San Gabriels.
- Workman & Temple Family Homestead Museum (El Campo Santo) — Follow up the wild boom-and-bust history of San Gabriel gold mining with a visit to the valley estate built by pioneer LA dynasts.
Good to know
Can you go inside the Big Horn Mine tunnels?
No. The U.S. Forest Service sealed the tunnel entrances behind heavy steel gates to prevent dangerous cave-ins and protect local wildlife.
How long and difficult is the hike?
It is a 4-mile round-trip hike from the Vincent Gap trailhead. The trail follows an old dirt road bed at high elevation with moderate inclines, but high heat and exposed sun make it feel longer.
Is the trail open year-round?
Trail and road access fluctuate frequently. Highway 2 closes regularly for winter snow and rockslides, and post-fire recovery efforts can trigger temporary forest closures, so check current forest service alerts before driving up.
Plan a visit & invite your people →
Further reading: Wikipedia · latimes.com · sfgate.com · californiathroughmilens.com · hikingguy.com · Reddit
last checked: 2026-07-20