At a Glance
- Distance: ~7.4 miles RT
- Elevation Gain: ~1,300 ft
- Difficulty: Moderate
- Trailhead: Tonahutu/North Inlet, RMNP
Green Mountain Trail
The Green Mountain Trail branches from the Tonahutu Creek Trail in Rocky Mountain National Park and climbs to a broad meadow below Green Mountain's summit. The meadow offers expansive views of the Never Summer Range and the western portion of RMNP — a perspective that few visitors experience since the trail starts from the less-traveled Grand Lake entrance.
The trail is approximately 7.4 miles round trip with moderate elevation gain — a solid half-day to full-day hike depending on pace and time spent in the upper meadow.
What You'll See
The lower trail follows Tonahutu Creek through dense spruce-fir forest before the Green Mountain branch climbs into more open terrain. The upper meadows are carpeted with wildflowers in July and gold aspen in September. Wildlife including elk, mule deer, and various bird species are common in the open terrain.
The Never Summer Range — a dramatic series of peaks along the western boundary of RMNP — forms the horizon from the upper meadow. The range is named for its persistent snowfields that remain through summer.
Accessing from Grand Lake Cabins
The trailhead is accessed from the Tonahutu/North Inlet area near the RMNP west entrance, approximately 5 minutes from Grand Lake Cabins properties. A park entry fee is required.
Combine the Green Mountain Trail with the Tonahutu Creek Trail for a longer loop option for experienced hikers.
One Trailhead, Four Very Different Days
The Green Mountain Trailhead sits at roughly 8,794 feet, about 3.5 miles north of the park entrance on Highway 34. What makes it useful is the spread of objectives from a single car park, which suits a group that wants to split by fitness rather than by destination.
Published figures give the Valley Trail at around 5.5 miles and rated easy; Granite Falls at roughly 5.2 miles with about 1,046 feet of gain, rated moderate; Haynach Lakes at around 8.3 miles with roughly 2,286 feet, rated difficult; and Flattop Mountain at about 10.3 miles with some 3,530 feet of climbing.
Reading Those Numbers Carefully
Other listings give Granite Falls as a 10.1-mile out-and-back and Haynach as 17.1 miles, which suggests the figures above are one direction rather than round trip. Plan on the longer version unless you have confirmed otherwise at the trailhead.
The gain figures are the more reliable guide to difficulty. Flattop Mountain at over 3,500 feet is a serious day at this elevation regardless of how the mileage is counted.
Splitting a Group
Because the easy Valley Trail and the demanding Flattop route leave from the same point, a group of twelve can genuinely divide for the day and reconvene without two cars and two plans.
From the cabins the park entrance is five minutes, with the trailhead a short run beyond. Every property has a full kitchen for packing lunches the night before, which matters more when half the group is out for eight hours.
Distances, elevation gain and difficulty above are drawn from published trail listings and are given as a guide. Published figures vary between sources, and trail conditions, closures and access change through the season. Check current conditions with the National Park Service at nps.gov/romo before setting out.