The Mother Road hauled it all, traversing the American West from Chicago to Santa Monica Beach, the last 350 miles through Southern California. For settlers, Depression-era Okies and Arkies, and post-World War II families bound for suburbia, Route 66 was a migration funnel for generations. Wending through the mountains and badlands of San Bernardino County into Los Angeles County, Route 66 became a state of mind and a catchphrase for travelers everywhere,...