The longest version of the Original Growler course.


5 - 6









FATMAP difficulty grade



Hartman Rocks has played host to mountain bike races since the dawn of the sport, thanks to nearby Crested Butte's claim to fame as the birthplace of mountain biking.

The original race held at Hartman's was known as "Rage in the Sage," and it was one of the first mountain bike races ever. In 2008, racing at Hartman Rocks was reborn, thanks to the motivation from a crew of ultrarunners who wanted to put together a 50k trail race at Hartman's, now known as the "Sage Burner Trail Race." The course for the trail running race ended up being about 32 miles.

The name for the mountain bike race takes its name from a growler of beer, which is 64 ounces.

So for a "Full Growler," you had to complete two laps on the course.

You could alternatively pedal a "Half Growler" by completing the course one time.

However, the "Full Growler" option has since been discontinued and replaced by a 40-mile loop option known as the "Big Bad 40." The 40-mile option is shown here and is formed by adding the Aberdeen Loop to the Classic 32.

The Aberdeen Loop is the most remote trail in the Hartman Rocks Trail System, providing an almost backcountry-style ride quality.

It's also incredibly scenic, providing stunning views and diverse terrain in Hartman's iconic high desert landscape.

It's also home to some of the longest climbs and descents in the trail system. While 40 miles of mountain biking might not sound like much to ultra-endurance riders accustomed to pedaling 100-mile centuries (or more), the Growler is renowned as one of the most technically-demanding endurance mountain bike races anywhere.

The vast majority of the 40-mile course traverses up-and-down singletrack filled with never-ending granite slabs, rock ledges, and chunky rock gardens.

After 40 miles of pedaling, even the best of riders will be challenged by the onslaught of rocks and punchy climbs. Riders will encounter a few sections of doubletrack and dirt road in the course, but these short sections have really only been added for passing opportunities right out of the gate and at key intervals on the course.

The rest of the loop consists of superb singletrack. The Hartman Rocks Recreation Area is located in the heart of the Gunnison Valley on a series of rolling sagebrush-covered hills and granite rock outcroppings.

While the topography isn't nearly as dramatic as the nearby Elk Mountains or San Juan Mountains, don't make the mistake of thinking this course is flat! The climbs might be short, but they're relentless, and the Big Bad 40 demands almost 5,000 feet of climbing! Registration for the Half Growler usually sells out within days, although demand for the Big Bad 40 is a bit less.

No matter which race distance you register for, you'll know that your entry fee is going to a good cause: this race is the primary fundraising event for Gunnison Trails, "a 501(c)3 non-profit trail advocacy organization.


.dedicated to maintaining and expanding the singletrack experience in the Gunnison area," according to the race's website. **Note:** All trails south of the Powerline Road—which includes the Aberdeen Loop—are closed seasonally from March 15th - May 15th for sage grouse habitat.

Please respect this seasonal closure—there is plenty of time to ride Aberdeen after May 15th. Sources: