On a long road trip last year, we logged all the plates we noticed. That included all 50 states plus Guam, Puerto Rico, federal government, and diplomatic plates. The article missed those not issued by states. What we didn't expect, and what the article also misses, is that we saw several distinct plate designs issued by Native Americans. We saw them in multiple states, but more in Oklahoma than anywhere else.

https://en.wikipedia.org/wiki/Vehicle_registration_plates_of...