Green Mountain, Gregory Canyon Trailhead, Boulder - Denver - Golden - Fort Collins - Lyons, Colorado

Green Mountain - 5.45 miles

Gregory Canyon Trailhead

Green Mountain and the Boulder Flatirons

Green Mountain and the Boulder Flatirons

Round-Trip Length: 5.45 miles
Start-End Elevation: 5,856' - 8,144' (8,144' max elevation)
Elevation Change: +2,288' net elevation gain (+2,328' total roundtrip elevation gain)
Skill Level: Strenuous
Dogs Allowed: Yes
Bikes Allowed: No
Horses Allowed: No
Related Trails:

Green Mountain - 5.45 Miles Round-Trip

The short but steep hike to Green Mountain (8,144') leads to a 100 mile panorama of the Continental Divide from the summit. As with many Boulder-area destinations there are several ways to get there -  the Gregory Canyon and Ranger trails offer the most direct route:

Trail Map | Photo Gallery

The Gregory Canyon Trail rises gently to a stream crossing (.55 miles), then climbs steeply on a twisting, rocky path to milder switchbacks in the upper canyon (1.0 miles : 6,650').

The Gregory Creek corridor supports apple and plum trees that attract bear and other wildlife. It's also covered with poison ivy, so remain on the trail at all times.

Travel eases considerably on a SW curl to the Ranger Trail - Long Canyon Trail split (1.3 miles : 6,655'). Merge left onto the Ranger Trail. The Ranger Trail remains flat to the historic Greenman Lodge (1.45 miles), past which it climbs methodically to the E.M. Greenman Trail split (1.75 miles : 6,950').

Here the Ranger Trail steepens on a series of tight switchbacks. Gaps in the forest offer a glimpse of snow-capped peaks to the west, a welcome sight along an otherwise business-like climb.

The Ranger Trail climbs to the Green-Bear Trail - Green Mt West Ridge Trail split along a narrow ridge below the summit (2.55 miles : 7,860'). Turn left toward Green Mountain.

The final 300 yards weave quickly through faint and rugged terrain to the summit. Tree markings offer guidance on the final approach. Scramble up the rock pile on Green Mountain's summit to reach a peak-finder that identifies peaks across a 100 mile panorama (2.72 miles : 8,144').

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.

Facebook Comments

Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N39 59.845 W105 17.572 — 0.0 miles : Gregory Canyon Trailhead
  • N39 59.874 W105 18.013 — .5 miles : Cross stream to south side of canyon
  • N39 59.847 W105 18.340 — 1.0 miles : Switchbacks level in upper canyon, where trail curls SW
  • N39 59.615 W105 18.493 — 1.45 miles : Ranger Trail - Greenman Lodge
  • N39 59.409 W105 18.315 — 1.7 miles : Ranger Trail - EM Greenman Trail split
  • N39 59.082 W105 18.229 — 2.3 miles : Steady climb on the Ranger Trail
  • N39 58.970 W105 18.229 — 2.55 miles : Ranger Trail - Green Bear Trail junction
  • N39 58.915 W105 18.095 — 2.72 miles : Green Mountain (8,144')

Worth Noting

  • Steep sections, especially on north-facing slopes, can be snow covered through mid-spring. Hiking poles or traction devices are recommended during this period.

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

  • Bears and other wildlife rely heavily on fruits and berries in Gregory Canyon. Avoid going off-trail, and leave fruits and berries to the local wildlife.

Rules and Regulations

  • Bikes and motorized vehicles are not permitted on the Gregory Canyon Trail or Ranger Trail.

  • There is a parking fee at the Gregory Canyon Trailhead 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 Chautauqua 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

City of Boulder Open Space and Mountain Parks
Phone: 303.441.3440

Trip Reports

There are no trip reports on this trail.


"Wonderful hike! Two things to know: 1) The Gregory Canyon Trail is currently thick with POISON IVY. If you don't pick your way extremely carefully or if you have a dog with you, there will be poison ivy contact. 2) The upper part of E.M. Greenman from Saddle Rock Trail to the summit is CLOSED TO DOGS. You can avoid most of the poison ivy by starting at Chautauqua at the Baseline Trail to Amphitheater Trail to Saddle Rock Trail, then take E.M. Greenman up to the top if you don't have a dog. Hikers with dogs can take E.M. Greenman down from the junction with Saddle Rock Trail, then pick up the Ranger Trail and take the Ranger Trail to the top. "
Laura  -  Boulder, CO  -  Date Posted: August 29, 2016


Add Comment

Only used to identify you to ProTrails. Will not show on comments list.
Tell us when your experience with this trail happened.