Entry No. 119 — the Denver file — filed under: history
Edgar Experimental Mine
This isn't a tourist gold mine with fake gunfights — it's the Colorado School of Mines' actual working research mine, where engineering students learn to drill, blast, and survey in half a mile of 1870s tunnels. Lately it's gone weirder: under ~200 meters of rock the school built the Colorado Underground Research Institute (CURIE), including a room nicknamed the Subatomic Particle Hideout where muon and neutron detectors run quantum and particle-physics experiments shielded from cosmic rays. Public hard-hat tours wind through the historic workings at a constant 54 degrees year-round. Almost nobody outside the geek pipeline knows you can just book a tour.
The story
In the 1870s, miners pounded into the mountain face above Idaho Springs chasing silver, gold, lead, and copper veins along the Edgar vein. By 1921, the Big Five Mining Company began leasing half a mile of those dark underground drifts to the Colorado School of Mines so engineering students could practice rock drilling, blasting, and mine surveying without risking commercial output. Mines eventually acquired the entire facility, fitting the historic timbered shafts with subterranean Wi-Fi, heavy mucking equipment, and simulated rescue chambers to create an active university field laboratory.
Deep inside, under roughly 200 meters of solid rock, the mine has taken on an even stranger role. That thick granite shield overhead blocks cosmic radiation, allowing the university to establish the Colorado Underground Research Institute (CURIE). In a chamber nicknamed the Subatomic Particle Hideout, researchers operate muon and neutron detectors for particle physics and quantum computing experiments. You aren't visiting a tourist trap with staged gunfights; you're walking through a working half-mile drift where engineering students detonate explosives and test subterranean sensors right next to high-tech physics labs.
What it's like
Drive up I-70 to Idaho Springs, turn onto 8th Avenue, and climb the steep hill past the main gate to park near the mine office. Inside the mountain, temperatures hover at a damp 54°F year-round, making a fleece jacket and sturdy closed-toe boots mandatory even during a summer heatwave. Once strapped into a provided hard hat, a student or faculty guide leads you down the main haulage tunnel past pneumatic drills, rescue chambers, and underground classrooms. Public tours run strictly by advance reservation and waitlists fill up fast. While entry directly into the CURIE quantum lab depends on active research schedules, guides point out the particle-physics branches and working research gear along the way.
The move: Book a guided hard-hat tour, go deep into the cold dark tunnels together, and have them point out the quantum/particle-physics gear before you surface for daylight and a thaw-out lunch in town.
📍 Before you go The mine sits above Idaho Springs, about a 40-minute drive west of Denver on I-70 — take exit 240, head north to Colorado Boulevard, then west to 8th Avenue, where the road climbs to the mine at the top of the hill. Drive through the main gate and continue up roughly a quarter mile to the office; there's parking on site. Tours run only by reservation and waitlists are common, so plan ahead rather than dropping in. Wear sturdy closed shoes and bring a warm layer — the tunnels stay genuinely cold year-round. Any season works since you're underground, but pair it with the historic downtown below: Idaho Springs has old mining-town pizzerias and hot springs to thaw out in afterward.
- 📍 Idaho Springs
- 💸 $
- ⚡ Up for anything
- 🌗 Indoors
Where: 365 8th Avenue, Idaho Springs, CO 80452 (Colorado School of Mines Edgar Experimental Mine)
Hours: Tours by appointment; contact mining@mines.edu or 303-567-2911. Public tour times appear via Mines' ticketing site and fill up (waitlists common). Note: the CURIE quantum lab is an active research space and not guaranteed on every public tour — confirm when booking. Mine is a constant 54°F; bring a layer.
Pair it with
- Indian Hot Springs Geothermal Caves — Soak in steam-filled geothermal mineral caves right down the road to thaw out after an hour in the cold 54-degree rock tunnels.
- Underhill Museum — Explore the preserved Victorian home and office of a historic local mining engineer less than a mile down the hill in town.
- Charlie Tayler Water Wheel — Walk down to Clear Creek to see a 30-foot wooden waterwheel constructed in 1893 by a local miner.
- Chief Mountain Trail — Contrast half a mile of dark underground granite with a short, panoramic ridge hike along CO-103 overlooking Mount Blue Sky.
Good to know
How do I book a tour of the Edgar Experimental Mine?
Public hard-hat tours run by appointment through the Colorado School of Mines ticketing system. Spots fill quickly and waitlists are common, so you must reserve online in advance or contact mining@mines.edu rather than dropping in.
What should I wear underground?
Bring a warm layer like a sweater or jacket and wear sturdy closed-toe shoes or boots. The mine remains at a chilly 54°F year-round with damp rock floors, and hard hats are provided at the entrance.
Will I get to see the CURIE quantum lab on the public tour?
Because CURIE is an active research space, direct entry into the quantum lab rooms is not guaranteed on standard public tours. Guides highlight the subatomic research areas and physics gear along the main drift when possible.
Is the mine accessible for strollers or wheelchairs?
No. The historic 1870s mine features unpaved rock floors, utility lines, and tight passageways that cannot accommodate wheelchairs or strollers.
Plan a visit & invite your people →
Further reading: mining.mines.edu · uncovercolorado.com · cpr.org · minesnewsroom.com · Reddit
last checked: 2026-06-07