I noticed that I'm not credited with about 4 miles of US 277 east of Chickasha even though I logged it as US 62. I found the problem: US 62 omits the waypoint at CR N2940 that is included on the logs of US 277 and OK 9, so US 62 isn't showing as concurrent for those 4 miles. Adding the identical waypoint on US 62 will make the concurrency complete again.