East of Taos, the South Boundary Trail (#164) is the premier Taos mountain biking route. It is typically ridden one-way from east to west starting near Angel Fire Resort and ending back near Taos. With a shuttle to up near Angel Fire, the ride starts with over a 2,000 foot vertical climb to Osha Peak (10,770 feet) before the 4,700 foot vertical descent over 20 miles. The South Boundary Trail rolls through old growth, ponderosa pine forests and paintbrush meadows of pinon-juniper in the Sangre de Cristo range. It finishes down in the cottonwoods along the Rio de Don Fernado. Combining singletrack with some doubletrack, it is typically a 4 to 6 hour ride.
While some hardcore riders will do the South Boundary Trail as an out-and-back from the western El Nogal Trailhead, most riders use a shuttle to one of the two eastern trailheads and ride west down to El Nogal Trailhead (7,300 feet). At the El Nogal Trailhead, you can ride the roads for 3 miles back down into Taos. Some of the Taos bike shops have offered shuttles in the past.
There are two eastern trailhead options. The most popular option is the eastern trailhead off FS70. Starting from the FS70 trailhead, head south for 5.3 miles climbing 1,400 feet to the main intersection with the route coming from the eastern Angel Fire trailhead. When coming from the eastern Angel Fire trailhead off SR434, head west for 2.6 miles climbing 1,000 feet to the main intersection. From the intersection, the South Boundary Trail runs 19.3 miles climbing over Osha Peak before descending down the long rolling route to El Nogal Trailhead.
After a long day of Taos mountain biking, try grabbing a long soak in one of the two primitive hot springs along the shores of the Rio Grande River. The Manby Hot Springs are located northwest of Taos and north of the Taos Airport. Also known as the Stagecoach Hot Springs, the trailhead is accessible from Tune Road across from the airport (lat: 36.512144 / long: -105.718169). The Black Rock Hot Springs are located northwest of Taos and west of Arroyo Hondo near the John Dunn Bridge. Also known as the the Hondo Hot Spring, the trailhead is located off CR8007/8005 on the west side of the John Dunn Bridge and then a half mile hike south down the trail (lat: 36.532597 / long: -105.712026).
To reach the eastern FS70 trailhead from Taos, head west on US64 (aka Kit Carson Road) for 19 miles to FS70. Turn right heading south on FS70 for about a mile. The trailhead may not be signed.
To reach the eastern Angel Fire trailhead from Taos, head west on US64 (aka Kit Carson Road) for 21 miles to SR434. Turn right heading south on SR434 for about 3 miles. The trailhead may not be signed.
To reach the El Nogal Trailhead from Taos Plaza, head east on US64 (aka Kit Carson Road) for 3 miles. About 0.3 miles past the intersection with SR585 and just past the National Forest sign, look for the well-signed El Nogal Trailhead parking area on the south side of US64. There is parking for about 20 vehicles without trailers.
Overall, South Boundary Trail is the 3rd most popular mountain bike trail of all 53 mountain biking rides in New Mexico.