Entry No. 64 — the Missoula file — filed under: abandoned-mine
1890 Historical Copper Mine
Dug into the western slopes of Mount Sentinel around 1890, this small, short-lived copper mine was a failed speculative venture during Montana's copper boom. Today, hikers can find the abandoned horizontal adit cut directly into the rocky hillside along the mountain's trail network. While the tunnel has been cleared of graffiti by local volunteers, it remains a dark, empty reminder of Missoula's minor mining history.
The story
While Butte was choking on smoke and swimming in copper billions around 1890, prospectors with more hope than capital were hacking at whatever rock they could find across Western Montana. On the steep, grassy western flank of Mount Sentinel, a few hopeful wildcatters hand-dug a narrow horizontal adit straight into the hillside. They were betting everything on a copper vein that ultimately wasn't there.
The venture collapsed almost as fast as it began, leaving behind a short, hollow tunnel in the rock face while Missoula grew into a town of timber, rails, and academia rather than mining barons. For over a century, the abandoned shaft sat mostly forgotten above the valley floor, occasionally picked at by nature or defaced by bored teenagers.
In recent years, local volunteers scrubbed the adit clean of graffiti, returning the rocky portal to a stark, unembellished state. It stands today as an eerie, silent pocket off the main trail network—a physical monument to late-19th-century speculative fever hiding in plain sight above the Clark Fork.
What it's like
You will reach the mine while navigating the Mount Sentinel trail network, often off routes connecting near the 'M' or the Hellgate Canyon loops. The site itself is a dark, rough-cut opening yawning out of the mountain's exposed rock. Standing at the threshold, you get a cool blast of subterranean air and a direct view out over the river valley, but keep your boots firmly outside—the unmaintained timber and stone overhead are structurally unpredictable, making flashlight-poking from the trail the only sensible way to inspect it.
The move: Hike up the scenic Mount Sentinel trail system together to locate the historic mine entrance, enjoying panoramic views of Missoula and the Clark Fork River Valley from the hillside.
📍 Before you go The mine is located on public land along the Mount Sentinel trail system and can be legally hiked to, but entering the dark, unmaintained adit is structurally unsafe and highly discouraged.
- 📍 Missoula
- 💸 Free
- ⚡ Low-key
- 🌗 Outdoors
Where: V23G+X7, Missoula, MT 59801, USA
Hours: Added 2026-07-20 — confirm current access before you go.
Pair it with
- Reinhardt Peony Garden on the 'M' Trail — Start or end your trek down at the base of Mount Sentinel to contrast the dry, rocky copper mine with this quiet garden right by the main trailheads.
- Philip L. Wright Zoological Museum — After looking at an empty 1890 hole in the mountain, drop down to the nearby UM campus to examine thousands of taxidermied Montana species preserved since the late 1800s.
- GILD Brewing (Basement Arcade) — Trade a cold, dark mountain adit for a warm, subterranean pinball bar built into river-rock basement walls on the Hip Strip.
Good to know
Can you go inside the mine tunnel?
No. The adit is unmaintained, structurally unsafe, and entering it is highly discouraged. You can safely view the horizontal entrance directly from the public trail.
How do you get to the mine site?
It is located along the Mount Sentinel trail system on public land, reachable via hikes like the Hellgate Canyon loop or trails leading up Mount Sentinel's western slope.
Is there an entry fee or set opening hours?
No, it is on open public land along hiking trails. Access is free, though you should always check trail access and weather conditions before hiking up.
What was actually mined here?
It was dug as a speculative copper mine around 1890, but it was short-lived and produced very little before being abandoned.
Plan a visit & invite your people →
Further reading: missoulian.com · worldatlas.com · alltrails.com
last checked: 2026-07-20