Arizona State Route 51 (SR 51), also known as the Piestewa Freeway, is a numbered state highway in Phoenix, Arizona. It connects Interstate 10 just outside Downtown Phoenix with Loop 101 on the north side of Phoenix, making it one of the area's major freeways. It is a largely north–south route and is known for traversing the Piestewa Peak Recreation Area. The peak was named after Lori Piestewa, the first Native American woman to die in combat in the U.S. Military. Prior to this time, the freeway was known as the Squaw Peak Parkway, a name considered offensive by many Native Americans. Rapid growth and increased traffic demand on the east side of Metro Phoenix made the Piestewa Freeway necessary.