High Quality Content by WIKIPEDIA articles! U.S. Route 163 (also U.S. Highway 163, US 163) is a 64-mile (103 km) U.S. Highway that runs from US 160 northward to US 191 in the U.S. states of Arizona and Utah. The southernmost 44 miles (71 km) of its length is within the Navajo Nation. The highway forms part of the Trail of the Ancients, a National Scenic Byway. The highway cuts through the heart of Monument Valley and has been featured in numerous movies and commercials.