Bureau of Land Management, New Mexico.
Horsethief Mesa Trail is about a 12-mile loop that is rated an intermediate level of difficulty with some technical, rocky sections.
Take 64 West out of Taos to stoplight at junction US64, NM 150, NM522
Go straight on NM 522 toward to Arroyo Hondo
Go .8 miles after road bridge in Arroyo Hondo, up hill
Go left on Old State Rd 3 (B001)
Quick right onto Tres Loma Rd
Follow main road to right and down hill
Bottom of hill, stay left on main road (stay off private road to Spanish Peaks)
Go past sub station
Go up short hill until road intersects with barbed wire fence opening (small public lands sign)
Take road to the right and uphill, then follow downhill
Park near small clearing and get on bike
Look for single track several yards ahead and to the right
This would take you counter clockwise on the trail loop