Four Mile Canyon and the Switzerland Trail are favorites of ours for gravel biking in the Boulder area. We have posted a similar route before, but this time coming off the Switzerland Trail, we explored going West on Gold Hill Rd to Sawmill Rd. (If you are interested in a “smash-up” of the best of those two rides, as ambassadors of People for Bikes‘ Ride Spot app, we posted that here: https://ridespot.org/rides/162302.)
As usual, a route like this one highlights the joys of gravel riding in Boulder: limited cars, great views, tons of different surfaces, challenging climbs and quickly getting you away from the city and into the mountains.
Boulder had a few late-season snows this year, but we were pleasantly surprised to find that all the high-elevation roads are now completely snow-free as of May, 10th 2020.
Switzerland Trail is generally very quiet and all of the Jeeps we encountered were courteous when we passed. We did not find the same when it came to the ATVs and dirt bike drivers. They sped past at alarming speeds and threw a lot of dust in the air!
Crossing Highway 36 to get to Neva road is a bit sketchy. We had to wait quite a while to find a break in traffic in order to safely cross.
Do this ride if you want a long climb with mixed road surfaces and some technical challenges on rocky jeep trails. You’ll will earn the views at the top, and enjoy a smooth, fun and fast downhill on Left Hand Canyon.
There is still a little bit of construction on the paved part of Four Mile Canyon but it is no longer down to one way traffic with lights.
The Switzerland Trail is pretty rocky and rugged! We most recently rode this route with 700x35cm Panaracer Gravelking SK+ Tires (set up tubeless and pumped to 40 psi) and had no problems but could have been a little more comfortable on a slightly wider tire.
After you depart the city of Boulder, there are a few places along the way to stop for bathrooms but be prepared to carry what you will need to keep you going in terms of water and food. There are bathrooms at the Mount Sanitas Trailhead off of Sunshine Canyon and Buckingham Picnic Area off of Left Hand Canyon.
We parked near the The Sports Garage bike shop in Boulder where there is plenty of easy street parking. (We love the friendly folks at The Sport Garage, so don’t hesitate to stop in!)