U.S. Route 450

U.S. Highway 450 was part of the original 1926 federal highway system, and was a spur of U.S. Highway 50. U.S. 450 ran from Walsenburg, Colorado to junction U.S. Highway 50 about 24 miles east of Green River, Utah. By 1939, it had been replaced by a westward extension of U.S. Highway 160. In 1970, U.S. 160 was diverted southwesterly from Cortez, Colorado to follow its present route past the four corners into Arizona. The northwesterly routing became a northward extension of U.S. Highway 666. Some time later, the portion in Utah between Monticello, Utah and Green River was renumbered U.S. Highway 163. In 2004, the portions of U.S. 666 in New Mexico, Colorado, and Utah were renumberd U.S. Highway 491.