U.S. Route 491, is a north-south U.S. Highway serving the 4 Corners region of the United States. One of the most recent designations in the U.S. Highway system, it was formed in 2003 as a renumbering of U.S. Route 666. In this highway run through the Colorado, New Mexico & Utah, with the tribal nations of the Navajo Nation & Ute Mountain Ute Tribe.