This ride combines the moderate grades and rocky, sandy surface of the Switzerland Trail
, a former narrow gauge rail grade - now jeep road, with the smooth packed dirt and bigger climbs of Gold Hill Road to close the loop.
The rail grade has many spectacular views of Fourmile Canyon and the Continental Divide as it traverses the valley. A short segment of pavement on Peak to Peak Highway completes the loop.
Services can be found in Nederland a few miles south on Peak to Peak Highway.
Park at the USFS Sourdough Trailhead parking lot on CR #116. Ride back out and then right and south about two miles on the Peak to Peak Highway, then turn left onto Switzerland Trail
. There is an extended gradual downhill on this jeep road all the way to Fourmile Creek. Stay left when you come to the Sugarload Trailhead parking area to keep on Switzerland Trail
The trail crosses Fourmile Creek at CR #118, passing through a few houses, then begins to climb back out of the canyon. The climb is gradual, this being a former rail grade, but you'll have to pick your lines between embedded rocks at times. The trail levels out near a large chimney and picnic area, the lone remnant of a former day lodge.
Not long after this, the trail crosses Gold Hill Road. You can shortcut the last bit of Switzerland Trail
by turning left here, avoiding a narrower, wetter part of the trail, but I prefer to continue on Switzerland Trail
until it intersects Sawmill
Road later. Sawmill
Road cuts through Switzerland Trail
, requiring a short, but steep and loose hike-a-bike up the embankment.
Turn left onto Sawmill
Road and climb up and over the ridge to the intersection with Gold Hill Road. Turn right onto Gold Hill Road and continue over its many deceptively steep climbs to the intersection with Peak to Peak Highway. You can ride pavement all the way back to Sourdough Trailhead parking by turning left on the highway, but I like to drop the small trail at the back of the parking lot at the intersection, descend through a dispersed camping area, and follow FS #328 across the Fourmile Creek valley, then up the other side to reduce time on pavement.
There is another short hike-a-bike climbing the embankment back onto Peak to Peak Highway. Turn left on the highway and ride a short distance to turn right on CR #116 and back to your car.
The Switzerland Trail
was once the C&N railroad connecting the mining towns of Eldora, Nederland, and Ward with Boulder. As mining declined, attempts were made to make it a scenic railroad, and local tourists rode it on outings to the mountains.The remnants of a massive fire place along the Switzerland Trail
mark the site of a former day lodge. In the early 1900s, a flood washed out many trestles and the line closed.