Trail Description

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The short but challenging hike to Green Mountain rewards visitors with exceptional views of Boulder County's back range, Indian Peaks, Continental Divide and Rocky Mountain National Park. As with many Boulder-area destinations, there are several ways to get there. The Gregory Canyon and Ranger Trails form the most direct route, and arguably most scenic.

The Gregory Canyon Trail rises quickly to a small stream crossing (.55 miles), then climbs steeply over twisting, rocky terrain before leveling over smooth switchbacks in the upper canyon (1 mile : 6,650’). The Gregory Creek riparian corridor boasts an array of summer wildflowers, and supports rather prolific apple and plum trees that attract bears and other wildlife. It's also covered with poison ivy, so year-round vigilance is advised.

Easing considerably, the trail bends southwest to the Ranger Trail – Long Canyon Trail junction (1.3 miles : 6,655’). Merge left onto the Ranger Trail. It remains flat to the historic Greenman Lodge (1.45 miles), beyond which it resumes a steady, moderately steep pace beneath Douglas Fir to the E.M. Greenman Trail junction (1.75 miles : 6,950’).

From here the Ranger Trail rises sharply on a sequence of tight, irregular switchbacks. Occasional openings in the dense forest offer a glimpse of snowcapped peaks to the west, a welcome sight along an otherwise yeoman-like climb. Fringe season hikers should be vigilant, as lingering snow may obscure unpredictable turns and lead you astray.

The Ranger Trail intersects the Green-Bear Trail and Green Mt West Ridge Trail atop a narrow ridgeline (2.5 miles : 7,860’). Turn left toward Green Mountain. These final 300 yards are faint and rugged, weaving quickly through colorful boulders, pine and fir stands to the summit. Tree markings offer guidance on the final approach. The needle-like rockpile summit (2.7 miles : 8,144’) features a peak-finder that will help deconstruct the mountainous panorama before you.

Gregory Canyon is named for John Gregory, an ambitious miner who in the 1860s built a road up the canyon to gold mines in the Black Hawk area. Though serviceable for several decades, the road’s rudimentary construction and canyon’s steep pitch were prohibitive, and eventually Flagstaff Road was completed in 1906 to replace it. The Ranger Trail’s origin is often attributed to Martin Parsons, a dedicated local ranger in the early 1900s. Apple trees in lower Gregory Canyon were likely planted by Ernest Greenman, who’s credited with planting hundreds of apple trees throughout the Boulder foothill canyons.

GPS Coordinates - DATUM WGS84

• N39 59.845 W105 17.572 - Gregory Canyon Trailhead

• N39 59.860 W105 18.024 - Cross stream over bridge

• N39 59.780 W105 18.273 - Switchbacks lengthen and ease

• N39 59.849 W105 18.345 - Switchbacks end in upper canyon; bear southwest

• N39 59.746 W105 18.494 - Ranger Trail - Long Canyon Trail junction

• N39 59.610 W105 18.493 - Greenman Lodge

• N39 59.409 W105 18.315 - Ranger Trail - EM Greenman Trail junction

• N39 59.082 W105 18.229 - Ranger Trail 2.3 mile mark

• N39 58.970 W105 18.229 - Ranger Trail - Green Bear Trail junction

• N39 58.915 W105 18.095 - Green Mountain Summit

Worth Noting

• Steep sections, especially on north-facing slopes, can be snow covered through mid-spring. Exercise caution and patience.



• Poison Ivy grows along the beginning of this trail system.



• No mountain bikes allowed.



• There is a parking fee if your car is not registered in Boulder County.

Directions to Trailhead

The Gregory Canyon Trailhead is located at the West end of Baseline Road in Boulder, Colorado.

Directions to Trailhead (from Boulder): Take Baseline Road West past Chatauqua Park to the Gregory Canyon Trailhead access road and turn left. Park when you reach the dead-end. Parking is limited at the trailhead; arrive early to secure parking.

Contact Information

Boulder County Parks & Open Space
5201 St. Vrain Road
Longmont, Colorado 80503
Phone: 303.678.6200
Fax: 303.678.6180
www.co.boulder.co.us/openspace