The Taos Mountain Trail was the historic pathway for trade and business exchanges between agrarian Taos (New Mexico) and the Great Plains (Colorado) from pre-history (1100 A.D.) through the Spanish Colonial period and into the time of the European and American presence. The Taos Mountain Trail, between northern New Mexico and southern Colorado, connected the high mountain traders and their trading partners north and south of the Sangre de Cristo Mountains. Also called the Trapper's Trail, the pathway was only wide enough for people on foot or horses in single file, but it shortened a trip from Taos to the plains farther north from nearly two weeks to three days in good weather. The Taos Mountain Trail was also known as the Sangre de Cristo Trail and the Aztec Trail.