Is it right for you?
Boulder Mountain is a mostly Class 1, barely Class 2 summit up Baldwin Gulch near St. Elmo. Old mining roads cover most of the way up, with grassy tundra and some rocky talus near the top.
From the bottom of the Baldwin Gulch road you walk up to Road 279, switchback up the northeast slopes, leave the trees near 12,100 feet, and climb to the northeast ridge near some old mine holes. A faint trail leads over a false summit to the top. Easy enough for families with younger kids.
The round trip is about 13 miles with 4,150 feet of gain from the lower trailhead. A shorter line leaves the road at its second switchback and follows the northeast ridge through open forest to the mine, then up the ridge: about 7 miles and 4,100 feet. The old roads may be open to ATVs and 4WDs, but they are rough with drop-offs and tight turns. Mount Mamma is about 2 miles away along a ridge.
Plan of the day
By 6:30 a.m.
Be at treeline by 10:30 a.m.
Just the distance.
Easy. Stay on Road 279 until just before the mine area.
Baldwin Creek low down. Filter it.
This week on the summit
Conditions on the summit
Loading Fetching the forecast for 13,530'…—
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Afternoon storm risk is the line that matters. Everything else is comfort. In summer, plan to be off the ridge before the build-up starts, not as it starts. Forecast for the summit point, adjusted for its elevation · data from Open-Meteo.
Getting there
Baldwin Gulch (lower)
South of Buena Vista, U.S. 285 and U.S. 24 meet. Head south on 285 from that junction for roughly 5.5 miles, and past Nathrop take a right (west) onto Chaffee County Road 162. This road goes up the Chalk Creek valley; the pavement stops at about 10 miles. At nearly 12.5 miles, watch on the left for the signed Baldwin Gulch road, also known as the 277 road.
Passenger cars park at pull-offs along County Road 162 near the bottom of the Baldwin Gulch road. The 277 road is steep, rocky and narrow, and only short-wheelbase, high-clearance 4WD vehicles should try it. Drive slowly and be ready to back up for oncoming traffic. There are dispersed campsites along the road above the creek crossing near 10,850 feet. Snow can block parts of the road into early July.
Fee campgrounds along County Road 162 (Bootleg, Mount Princeton, Chalk Lake, and Iron City on the way to St. Elmo) fill up on weekends. There are a few primitive sites a short way up Road 277 past the split, and more on Road 278 just after the creek.
Base towns and camping for this climb
Coming from out of state? See Lodging & Camping for how free camping works, what is closed this year and where to stay.
Before you go
Check these the week of your climb.
Official forecast
The National Weather Service forecast for the summit area, hour by hour. Look for thunderstorm chances and wind above treeline.
NWS point forecast →Directions to the trailhead
Baldwin Gulch (lower). Road conditions near the trailhead change after storms. Check your clearance and have a backup plan for a lower lot.
Get directions →Roads and highways
Closures, construction and winter conditions on the highways that get you there.
COtrip road conditions →Closures and fire rules
Trail closures, fire bans and other alerts from the Forest Service in Colorado. For the latest on your trailhead, call the local ranger district.
Forest Service alerts →Snow on the route?
From fall through early summer, any snow slope can slide. Check the avalanche forecast before you go.
Avalanche forecast →Cell signal
Most trailheads and many summits have little or no signal. Check coverage near the trailhead and carry a satellite messenger or beacon if you can.
FCC coverage map →