Mid-October is the sweet spot for the South Boundary Trail, and also the warning bell. The aspens along this high-country route between Angel Fire and Taos are at their brightest right now, and the window before snow closes the upper trail is getting short. For hikers, riders and mountain bikers who have been putting it off all summer, this is the week to go.
The South Boundary Trail, Forest Service Trail 164, is a National Recreation Trail in the Carson National Forest and one of the best-known long rides in New Mexico. The National Forest Foundation describes it as 21.5 miles point to point, with about 1,600 feet of climbing and 4,400 feet of descending. It is open to hikers, equestrians and mountain bikes, and most people travel it in one direction with a shuttle rather than as an out-and-back.
Traditional access is from the Angel Fire side on the east end of the ridge. Other ways in include Mondragon Canyon, Forest Service Road 660, and a connection from Valle Escondido using Osha Pass Trail, Forest Service Trail 70, to Elliot Barker Trail, Forest Service Trail 1. The west end finishes at the El Nogal trailhead outside Taos. That final stretch deserves respect: the last few miles drop steeply over loose, rocky ground, and tired legs make it harder. Saving some energy, food and water for the finish is not optional on this route.
What makes the trail memorable is the steady change of country along the way. The route winds through alpine meadows, cool pine forest and quaking aspen groves on classic side-hill singletrack. In fall, the aspen sections are the draw, with gold leaves lighting up long stretches of trail. Shuttle operators who work the route note that aspen color typically runs from mid-September through mid-October, which puts this week right at the tail end of the show.
Planning matters more in October than it did in July. Start early, because daylight is shorter and temperatures at the high end of the trail, above 10,000 feet, fall fast once the sun drops. Carry layers, a map that does not depend on cell service, and more water than the distance alone suggests. Tell someone the plan and the expected finish time, and arrange the shuttle or pickup before leaving, not from the trailhead. Check current Carson National Forest alerts before heading out, and be ready to turn around if snow or ice appears on the upper sections.
Shorter tastes of the same country work too. Hiking or riding an out-and-back from either end gives the aspen groves and meadow views without committing to the full point-to-point distance. Either way, the South Boundary in fall is Carson country at its best: quiet, golden and demanding enough to feel earned. Go this week, go prepared, and enjoy it before winter takes the high country back.