Oregon law is kinda funny regarding the front license plate. The way the law is written, you're only required to have a front license plate if you are supplied with two
plates. If you are supplied with one
plate, it is required to go on the rear of the vehicle.
The law also states though that passenger vehicles are provided two plates, so I guess I couldn't just tell the officer that I was only sent one!
BTW, Portland police love to give tickets for not having a front plate. One of my co-workers has received two tickets in the last six months while he was parked on the street in downtown!