Switzerland Trail
The Switzerland Trail is an old narrow-gauge railroad grade in the mountains west of Boulder, now National Forest System Road 327, sitting at about 9,000 feet and open to driving, mountain biking, horseback riding, and walking.
Outdoor Boulder › Destinations › Switzerland Trail
Switzerland Trail quick facts
- Managing agency
- USDA Forest Service, Boulder Ranger District (Arapaho and Roosevelt National Forests). The route is National Forest System Road 327.
- Distance
- The Forest Service does not publish a length for the route. Its description covers the stretch between Boulder County Road 52 (Gold Hill Road) and Colorado Highway 72, and secondary sources disagree on the total, so we're not going to invent a figure.
- Elevation
- About 9,000 feet, per the Forest Service.
- Surface
- Dirt and rock road on an old narrow-gauge railroad grade, so the grade stays gentle even though the elevation is high.
- Allowed uses
- Road cycling, off-highway vehicle road riding, horseback riding, and walking. All motorized vehicles are restricted to routes designated open for their use.
- Fee
- No fee is listed for the road. Mount Alto Picnic Area sits alongside it.
- Best season
- Roughly June through October. It's a high, unplowed mountain road, so snow and mud close it in practice for much of the year.
What the Switzerland Trail actually is
Despite the name, it isn't a hiking trail and it isn't in Switzerland. It's a road: National Forest System Road 327, laid on the grade of the Denver, Boulder and Western narrow-gauge railroad. The Forest Service describes it as an old railroad grade that zigzags across the mountains of Boulder County, built to haul people, supplies, and ore between Boulder and the mining camps at Gold Hill, Ward, Cardinal, Nederland, and Eldora between 1883 and 1919.
That history is the whole reason it's pleasant to travel. Trains can't climb steep grades, so the route contours and switchbacks instead of going straight up, which means you get high-country scenery at roughly 9,000 feet without the punishing gradient of most Boulder foothill trails.
How to get to the Switzerland Trail
The Forest Service gives one set of directions: from Boulder, head west on Mapleton Avenue, which becomes Sunshine Canyon Drive, and continue toward Gold Hill. West of Gold Hill the route is Boulder County Road 52, also called Gold Hill Road, and the Switzerland Trail intersects it 2.5 miles west of the town of Gold Hill.
There's a second common approach from the south, up Boulder Canyon and then Sugarloaf Road, which brings you onto the route near its southern end. Both approaches are on unpaved mountain roads for the last stretch.
Driving it: what the agency does and doesn't say
The Forest Service publishes one restriction plainly: all motorized vehicles are restricted to routes designated open for their use. It does not publish a required vehicle class, a difficulty rating, or a seasonal opening date for this road. What we can tell you honestly is that it's a narrow, rocky, unmaintained-feeling mountain road where meeting an oncoming vehicle is genuinely awkward, and that conditions swing hard with weather. If you're at all unsure about your vehicle or your comfort on shelf roads, this is a great route to ride or walk instead of drive.
Biking the Switzerland Trail
The Forest Service lists road cycling and off-highway vehicle road riding as recreation opportunities here, and cyclists have the better end of the deal. The railroad grade is the gentlest sustained climbing you'll find at this elevation near Boulder. It's also long, dry, shadeless in stretches, and 9,000 feet above sea level, so treat it as a bigger day than the profile suggests and carry all your own water. If you're new to riding at altitude, read our Boulder elevation guide first.
Horses, picnicking, and Mount Alto
Horses and pack animals are allowed on this road, per the Forest Service. The Mount Alto Picnic Area sits alongside the route and is the obvious place to stop and eat. There's no water and there are no services out here, so bring what you need and pack it back out.
Season, snow, and fire restrictions
This is high, unplowed country. Realistically the road is a summer and early fall proposition, roughly June through October, and it can hold snow and deep mud well past when Boulder itself is dry. Fire restrictions matter here too: as of June 30, 2026, Boulder County had Stage 2 fire restrictions in effect for the western part of the county, which covers this area. Those change through the season, so check before you go rather than trusting a date on a web page, including this one.
Nearby trails and guides
- Bald Mountain Scenic Area: a short, high summit walk on the way up Sunshine Canyon.
- Betasso Preserve: the singletrack option in the same stretch of foothills.
- Biking around Boulder: paths, singletrack, and the big road climbs.
- Campgrounds near Boulder: where to sleep if you're making a weekend of it.
- Boulder elevation and altitude tips: what 9,000 feet does to you.
Switzerland Trail FAQ
Where is the Switzerland Trail and how do you get there?
It's in the mountains west of Boulder, on Forest Service land. The Forest Service's own directions run west on Mapleton Avenue, which becomes Sunshine Canyon Drive, and on toward Gold Hill. West of Gold Hill the road becomes Boulder County Road 52 (Gold Hill Road), and the Switzerland Trail intersects it 2.5 miles west of the town of Gold Hill. Many people also reach the southern end from Sugarloaf Road off Boulder Canyon.
Do you need four-wheel drive for the Switzerland Trail?
The Forest Service doesn't publish a vehicle-class requirement, just that motorized vehicles have to stay on routes designated open for them. In practice it's a rough, narrow dirt mountain road, so high clearance helps and conditions change with weather. If you're unsure about your vehicle, ride it on a bike or walk it instead.
How long is the Switzerland Trail?
The Forest Service doesn't publish a mileage, and the secondary sources that do don't agree with each other. What the agency does describe is the stretch between Gold Hill Road and Colorado Highway 72. Plan by time and turnaround point rather than by a total distance you read somewhere.
Can you bike the Switzerland Trail?
Yes. The Forest Service lists road cycling as a recreation opportunity here, and the old railroad grade is the reason: it climbs gently for a mountain route because trains had to be able to pull it. It's a long, exposed, high-altitude ride with no water, so carry more than you think.
What was the Switzerland Trail originally?
A railroad. The Forest Service describes it as an old narrow-gauge railroad grade that hauled people, supplies, and ore between Boulder and the county's mining towns, including Gold Hill, Ward, Cardinal, Nederland, and Eldora, from 1883 to 1919. The rails are long gone; the grade is what you're traveling on.
Are there fire restrictions on the Switzerland Trail?
Often, yes. As of June 30, 2026, Boulder County had Stage 2 fire restrictions in place for the western part of the county, which is where this road is. Restrictions change through the season, so check Boulder County's fire restrictions page and the Forest Service alerts before you plan a fire or use anything with a spark.
Sources
Facts on this page are drawn from these authoritative sources:
Last checked . We verify trail facts against the managing agency, and we say so when a figure isn't published.