Green Mountain Trail #110
Green Mountain Trail #110 (ref 110) is an 8.89 km long-distance hiking route in the Gifford Pinchot National Forest, northwest of Mt. Adams. The trail is open to hikers and horses, and it’s also used by bicycles and motorcycles, so expect significant multi-use traffic on the shared route segments.
Most hikers use the Horseshoe Lake area as a base, connecting into the route from nearby signed trail junctions. A common approach is to start from Horseshoe Lake Campground and then use the connector to link up with nearby High Lakes Trail #116, then reach the Green Mountain Trail #110 junction.
From the lower start the route climbs through Douglas-fir and silver fir forest with switchbacks, rising toward semi-open ridges. As you gain elevation, the terrain opens enough for south/Cascades views that continue as the trail works its way toward Green Mountain’s summit area.
On the climb, the route crosses small creeks on wooden bridges marked as built by motorized recreation groups. The ascent then becomes a steady series of switchbacks and traverses, with openings/bald edges that support wildflowers in early summer.
Green Mountain Trail #110 can be combined into a lollipop-style loop with nearby trails, including Spring Creek Trail #115 and High Lakes Trail #116, returning the way you came via the junctions near the Horseshoe Lake side.
Because the corridor is shared with motorcycle use, you may see motorcycle tracks and impacts near higher viewpoints/summit spur areas. It also runs through habitat where red baneberry occurs along the trail corridor west of Trail #115, so hikers should avoid handling plants.
Campers commonly pair this hike with Horseshoe Lake Campground (11 campsites on a small lake). The campground has vault toilets, no potable water, and is open mid-June through mid-September; OHV trail riding is available on Green Mountain Trail #110.
If you’re planning timing around seasonal use, low-elevation trail sections typically melt out by mid-May, while higher sections typically melt out by mid-July, with snow possible in isolated spots on north-facing slopes. Mosquitoes can be an issue in summer, especially in warmer months when trails are clear.
More information: Visitor information, Visitor information, Spring Creek - Green Mountain - Washington Trails Association