Portal:United States/Selected location/25

Interstate 15 in Arizona is part of Interstate 15 (I-15), a transcontinental Interstate Highway from San Diego, California, to the Canadian border. The highway segment passes through Mohave County in the far northwest corner of the U.S. state of Arizona. Despite its length of 29.43 miles (47.36 km) and isolation from the rest of the state in the remote Arizona Strip, it is notable for the scenic section through the Virgin River Gorge. The highway heads in a northeasterly direction from the Nevada border northeast of Mesquite, Nevada, to the Utah border southwest of St. George, Utah. The southern portion of the routing of I-15 was built close to the alignment of the old U.S. Route 91, but the northern section through the Virgin River Gorge was built along an alignment that previously had no road. The southern section of the highway was complete and opened in the early 1960s, while the section through the gorge did not open to traffic until 1973. When it opened, the portion of I-15 through the Virgin River Gorge was the most expensive section of rural Interstate per mile.