Entry No. 46 — the San Francisco file — filed under: mine

Leona Heights Sulfur Mine

The Leona Heights Sulfur Mine is a closed pyrite mine in the Oakland Hills that operated from about 1900 to 1934 to produce sulfuric acid. For decades after its closure, the site left behind toxic tailings that turned Leona Creek a bright, acidic orange. A major remediation project completed in 2015 permanently capped the waste piles, restored the creek, and sealed off the old mine tunnels.

The move: Hike the scenic York Trail in Leona Heights Park, which winds through second-growth redwoods and oak woodlands, and look for the restored Leona Creek.

📍 Before you go The mine is located on private property, fenced off from public trails, and the dangerous tunnels have been permanently sealed and covered during a 2015 environmental remediation project.

• 📍 Oakland
• 💸 Free
• ⚡ Low-key
• 🌗 Outdoors

Where: 5250 McDonell Ave, Oakland, CA 94619, USA

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

Plan a visit & invite your people →

Further reading: localwiki.org · waterboards.ca.gov · sfgate.com

last checked: 2026-07-20