Entry No. 72 — the Boulder file — filed under: historic

Santiago Mine

Perched at over 12,000 feet in the Waldorf Basin, the Santiago Mine and Mill is a remarkably preserved 1930s gold flotation mill. Originally constructed in 1935, the multi-level wooden structure still houses its original jaw crusher, ball mill, and flotation machinery. Today, the U.S. Forest Service and local stewards work to preserve the site, which is surrounded by dramatic alpine tundra.

The move: Drive a high-clearance 4WD vehicle up the rugged Argentine Pass trail to the Waldorf Basin, then walk the newly constructed interpretive trail around the exterior of the historic mill to photograph the towering wooden structure against the mountain backdrop.

📍 Before you go The exterior of the mill is legally viewable from a newly constructed public interpretive trail on U.S. Forest Service land, but entering the fragile, hazardous historic structures or any mine shafts is strictly prohibited.

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

Where: Santiago Mine, Colorado 80435, USA

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

Plan a visit & invite your people →

Further reading: Official site · fs.usda.gov

last checked: 2026-07-20