The Arizona state flag flies along old U.S. highway 66 in Mohave County, Arizona. Much of Route 66, America's best-known historic highway, which was known as the Mother Road, connecting Chicago, Illinois, and Santa Monica, California, in the heyday of cross-country family travel from the 1930s through the 1950s, has been subsumed by the nation's high-speed interstate highways. But a bending portion of the old, two-lane highway that survives in western Arizona still draws curiosity-seekers and nostalgia buffs. Photo by Carol Highsmith.