FATMAP difficulty grade
The 100,000-acre Fourmile Travel Management Area provides over 100 miles of roads and trails, many of which are perfect for gravel rides.
The Castle Rock Gulch route is one of the best! In Buena Vista, Colorado's beautiful, big backyard, spring and fall are truly spectacular seasons to take advantage of “Fourmile.” It is not highly traveled by motor vehicles and the temperatures are generally comfortable during these shoulder-seasons.
During the summer, both traffic and temps increase; during winter, it can get snowy and cold! The best place to start the loop is at the Bald Mountain trailhead just off CR187.
From the trailhead, CR187 is a steady climb that is scenic from the get-go.
As the route gains elevation, shortly after passing the intersection with 185 to Aspen Ridge, the majestic mountains of the Sawatch Range burst into view.
In the spring, the 14,000-foot-tall mountains are still cloaked in snow, providing a stunningly beautiful contrast to the dry, rocky, desert-like terrain of Fourmile. At the halfway point, CR187 ends at a four-way intersection, where the route takes a sharp left onto the more rugged 188.
From this point, the narrower dirt road takes riders on numerous short climbs, switchbacks, and fun descents as it heads into Castle Rock Gulch. Castle Rock Gulch is an absolutely beautiful area studded with immense rock formations, ponds, and glimpses of the 13,000-foot Buffalo Peaks.
Take note of 188A on the right, a mile long spur road that passes alongside the base of amazing rock formations.
At the end of the road, there are lovely campsites that would make for a wonderful overnight bikepacking destination.
It is also a great picnic spot, so be sure to pack a lunch.
Adding this optional spur out-and-back makes the total ride 17 miles long. Continuing on 188 closes the loop when it intersects with CR187 and travels back to the Bald Mountain trailhead.
This is the “lollipop stick” part of the route and is mostly a swooping descent.
Don't go so fast that you miss the chance to see bighorn sheep—they frequently hang out in the terrain along CR187.
You may even be lucky enough to spy a stately ram! Sources: https://garna.org/2013/wp-content/uploads/2013/07/Fourmile-Brochure-FINAL-4.26.17-web.pdf