Entry No. 39 — the Santa Barbara file — filed under: mine

Coquina Mine

Located in the Marr Ranch Open Space of Simi Valley, the Coquina Mine is an abandoned 1930s limestone quarry once operated by the Tapo Alto Shell & Fertilizer Company. Active from 1929 to 1935, the site was mined for fossil-rich limestone to produce calcium carbonate. Today, hikers can find rusted relics left behind, including a vintage P&H Model 206 power shovel and other decaying machinery.

The move: Hike the scenic Coquina Mine Trail together, enjoying views of the Santa Susana Mountains while photographing the historic, rusted mining equipment from a safe distance.

📍 Before you go The mine is located along a public hiking trail in the Marr Ranch Open Space, but visitors should remain on the trail and only view the unstable, rusted machinery and quarry site from a safe distance.

• 📍 Coquina Mine
• 💸 Free
• ⚡ Low-key
• 🌗 Outdoors

Where: Coquina Mine, California 93063, USA

Hours: Added 2026-07-20 — confirm current access before you go.

Plan a visit & invite your people →

Further reading: visitsimivalley.com

last checked: 2026-07-20