Switzerland Trail

In 1883 a narrow-gauge railroad crawled into these mountains to haul gold ore and, later, tourists in straw hats. The gold ran out; the grade remained. Today the Switzerland Trail is the friendliest rough ride in the Front Range — a railroad's idea of a climb (never more than 4%) surfaced with a century of decomposing granite.

Don't let the gentle grades fool you into bringing the skinny tires. This is chunk: fist-sized babyheads in the worst sections, loose kitty-litter granite in the best. On a mountain bike or a 50 mm gravel setup it's a rolling picnic. On 32s it's a hostage situation.

The loop circles Sugarloaf Mountain through lodgepole and aspen — in late September the entire western slope turns to fire, and this becomes the best leaf ride in Boulder County, full stop. Views open west to the Continental Divide at every old trestle cut.

There's no resupply up here and no signal for most of the lap, which is exactly the point. Pack real food, bring a layer (afternoons build storms out of nothing), and budget an unhurried half day.

It's the quietest route in this collection and the one I ride when I need the mountains to fix something. The railroad did the engineering; you just pedal through the history.