Interstate 17 (abbreviated I-17) , also known as Black Canyon Freeway, is an intrastate Interstate highway located entirely within the state of Arizona, United States. I-17's southern terminus lies within Phoenix, Arizona, at Interstate 10, and its northern terminus is in Flagstaff, Arizona, at Interstate 40. The southern part of the freeway was built along the alignment of SR 69, while the northern part was built along SR 79's alignment. Interstate 17 is one of the more scenic interstate highways as it gains more than a mile in altitude between Phoenix (1,117 feet) and Flagstaff (7,000 feet). The highway features several scenic view exits along its route that overlook the many mountains and valleys found in northern Arizona.