High Quality Content by WIKIPEDIA articles! The historic U.S. Route 66 ran from west to northeast across the U.S. state of Oklahoma, along the path now taken by Interstate 40 and State Highway 66. It passed through Oklahoma City, Tulsa, and many smaller communities. West of the Oklahoma City area, it has been largely replaced by I-40; the few independent portions that are still state-maintained are now Interstate 40 Business. However, from Oklahoma City northeast to Kansas, the bypassing Interstate 44 is mostly a toll road, and SH-66 remains as a free alternate.