Four Mile Canyon and Switzerland Trail to Gold Hill

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Boulder, CO
Date Published:
April 22, 2019
Gravel Ratio:
70% G / 30% P
Difficulty Rating:
Enjoyability Rating:
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Holy smokes, Boulder brings it again! This route highlights the typical joys of gravel riding in Boulder: limited cars, great views, tons of different surfaces, challenging climbs, and animal sightings.

The route started off on quiet roads with steep ascents. Just as we were getting tired, we had a great 15-mile descent down Left Hand Canyon and ended with a tour of Gun Barrel and Niwot on the Lobo gravel Trail.

We fell in love with Four Mile Canyon Road. It not only was a great gravel road but had quaint areas along the way. (Do they qualify as towns??!!) The atmosphere of Four Mile Canyon feels like a funky and fabulous combination of Europe, the Wild West and Yosemite!

Switzerland Trail is a forest/jeep road that connects Four Mile Canyon to Gold Hill.

It was the most technically challenging part of this route and it felt good to conquer it with confidence.


(In April, 2019) there was some construction on Left Hand Canyon and by Highway 119 that delayed us a bit.

This was our first ride since our epic 100-mile White Rim Trail adventure and we realized that we needed to service our disc brakes. We felt more than a little insecure and sketched out descending some of the steep gravel roads while squeezing our brakes as hard as we could and not slowing down adequately. Yikes!

Do this ride if you want a route that starts with a long and challenging climb on mixed-surfaces above Boulder that is nearly devoid of cars, features amazing views of the Continental Divide, then winds down on the flat and fast dirt roads of Niwot and Gun Barrel.

Other Notes:

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 some places along the way to stop for bathrooms and water but they not reliably open. Be prepared to carry what you will need to keep you going in terms of water and food.

It has been fun to learn how to best do gravel biking adventures. We watch the weather apps, we plan our route, we have exit strategies in case we get tired or something happens to our bikes, we look at the elevation profile and when parts of our route include dotted lines instead of clear gravel or paved roads on, we do a little more research to understand what the terrain and technical biking may be.
When we are exploring new routes, the security of GPS on our Wahoo Element is critical because it has the route pre-loaded and all we have to do is follow the dotted line. It allows us to relax, enjoy the ride and know that we can’t get (too) lost!

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!)

Driving Directions

Route Contributor

Laura & Rose

Laura Karpinski and Rose Barcklow are the creators of Gravel Bike Adventures. Click on the About page to learn more about them.

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